diff --git a/calculator.c b/calculator.c
new file mode 100644
index 0000000..00060f9
--- /dev/null
+++ b/calculator.c
@@ -0,0 +1,143 @@
+#include <stdio.h>
+#include "calculator.h"
+
+void handleCalc(struct calculator *calc, int input) {
+    switch (calc->state) {
+        case NUMBER_FIRST:
+            switch (input) {
+                case 0:
+                    calc->num1 = (calc->num1 * 10) + 7;
+                    break;
+                case 1:
+                    calc->num1 = (calc->num1 * 10) + 8;
+                    break;
+                case 2:
+                    calc->num1 = (calc->num1 * 10) + 9;
+                    break;
+                case 3:
+                    calc->operation = DIV;
+                    calc->state = NUMBER_SECOND;
+                    break;
+                case 4:
+                    calc->num1 = (calc->num1 * 10) + 4;
+                    break;
+                case 5:
+                    calc->num1 = (calc->num1 * 10) + 5;
+                    break;
+                case 6:
+                    calc->num1 = (calc->num1 * 10) + 6;
+                    break;
+                case 7:
+                    calc->operation = MUL;
+                    calc->state = NUMBER_SECOND;
+                    break;
+                case 8:
+                    calc->num1 = (calc->num1 * 10) + 1;
+                    break;
+                case 9:
+                    calc->num1 = (calc->num1 * 10) + 2;
+                    break;
+                case 10:
+                    calc->num1 = (calc->num1 * 10) + 3;
+                    break;
+                case 11:
+                    calc->operation = SUB;
+                    calc->state = NUMBER_SECOND;
+                    break;
+                case 12:
+                    calc->num1 = (calc->num1 * 10);
+                    break;
+                case 13:
+                    clearCalc(calc);
+                    break;
+                case 14:
+                    break;
+                case 15:
+                    calc->operation = ADD;
+                    calc->state = NUMBER_SECOND;
+                    break;
+            }
+            break;
+
+        case NUMBER_SECOND:
+            switch (input) {
+                case 0:
+                    calc->num2 = (calc->num2 * 10) + 7;
+                    break;
+                case 1:
+                    calc->num2 = (calc->num2 * 10) + 8;
+                    break;
+                case 2:
+                    calc->num2 = (calc->num2 * 10) + 9;
+                    break;
+                case 3:
+                    break;
+                case 4:
+                    calc->num2 = (calc->num2 * 10) + 4;
+                    break;
+                case 5:
+                    calc->num2 = (calc->num2 * 10) + 5;
+                    break;
+                case 6:
+                    calc->num2 = (calc->num2 * 10) + 6;
+                    break;
+                case 7:
+                    break;
+                case 8:
+                    calc->num2 = (calc->num2 * 10) + 1;
+                    break;
+                case 9:
+                    calc->num2 = (calc->num2 * 10) + 2;
+                    break;
+                case 10:
+                    calc->num2 = (calc->num2 * 10) + 3;
+                    break;
+                case 11:
+                    break;
+                case 12:
+                    calc->num2 = (calc->num2 * 10);
+                    break;
+                case 13:
+                    clearCalc(calc);
+                    break;
+                case 14:
+                    switch (calc->operation) {
+                        case ADD:
+                            calc->result = calc->num1 + calc->num2;
+                            calc->state = RESULT;
+                            break;
+                        case SUB:
+                            calc->result = calc->num1 - calc->num2;
+                            calc->state = RESULT;
+                            break;
+                        case MUL:
+                            calc->result = calc->num1 * calc->num2;
+                            calc->state = RESULT;
+                            break;
+                        case DIV:
+                            calc->result = calc->num1 / calc->num2;
+                            calc->state = RESULT;
+                            break;
+
+                    }
+                    break;
+                case 15:
+                    break;
+            }
+            break;
+        case RESULT:
+            switch (input) {
+                case 14:
+                    clearCalc(calc);
+                    break;
+            }
+            break;
+    }
+}
+void clearCalc(struct calculator* calc) {
+    calc->state = NUMBER_FIRST;
+    calc->operation = NO_OP;
+    calc->num1 = 0;
+    calc->num2 = 0;
+    calc->result = 0;
+}
diff --git a/calculator.h b/calculator.h
new file mode 100644
index 0000000..d183a36
--- /dev/null
+++ b/calculator.h
@@ -0,0 +1,32 @@
+#ifndef TESTCALC_MAIN_H
+#define TESTCALC_MAIN_H
+
+enum calculator_state {
+    NUMBER_FIRST,
+    NUMBER_SECOND,
+    RESULT
+};
+enum calculator_op {
+    NO_OP,
+    ADD,
+    SUB,
+    DIV,
+    MUL
+};
+struct calculator {
+    // 1 число
+    int num1;
+    // 2 число
+    int num2;
+    // 3 операция
+    enum calculator_op operation;
+    // 4 результат
+    int result;
+    // 5 состояние атомата
+    enum calculator_state state;
+};
+
+void clearCalc(struct calculator *calc);
+void handleCalc(struct calculator *calc, int input);
+
+#endif //TESTCALC_MAIN_H
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..2ef6498
--- /dev/null
+++ b/main.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+#include "calculator.h"
+
+int main() {
+    struct calculator calc;
+    clearCalc(&calc);
+    int input;
+    while (1) {
+        scanf("%d", &input);
+        handleCalc(&calc, input);
+        printf("num1: %d | num2: %d | result: %d | operation: %d | state: %d", calc.num1, calc.num2, calc.result, calc.operation, calc.state);
+    }
+}
\ No newline at end of file