#include <stdio.h>
float add(float num1, float num2, float num3);
float mult(float num1, float num2, float num3);
float sub(float num1, float num2, float num3);
void again();


void again() {
    puts("returning to the main menu!\n");
    int main();
}

float add(float num1, float num2, float num3) {

    float ans = num1 + num2 + num3;
    return ans;
}
float mult(float num1, float num2, float num3) {

    float ans = num1 * num2 * num3;
    return ans;
}
float sub(float num1, float num2, float num3) {

    float ans = num1 - num2 - num3;
    return ans;
}

int main() {
    float num1, num2, num3;
    puts("Enter a b c\n");
    scanf_s("%f %f %f", &num1, &num2, &num3);
    int op;
    puts("Enter 1 for addition\nEnter 2 for multiplication\nEnter 3 for subtraction\n4 to return to main menu\n");
    scanf_s("%d", &op);
    if (op == 1) {
        float ans = add(num1, num2, num3);
        printf("result of op1: %f", ans);
    }
    else if (op == 2) {
        float ans = mult(num1, num2, num3);
        printf("result of op2: %f", ans);
    }
    else if (op == 3) {
        float ans = sub(num1, num2, num3);
        printf("result of op2: %lf", ans);
    }
    else if (op == 4) {
        again();
    }

}