#include <stdio.h>

int main( void )
{
    int a, b, sum;
    float a2, b2, sum2;
    double a3, b3, sum3;

    printf("enter two integers, and I will print out their sum:\n");
    scanf("%d %d", &a, &b);
    sum = a+b;
    printf("a + b = %d\n\n", sum);

    printf("enter two real numbers, and I will print out their sum:\n");
    scanf("%f %f", &a2, &b2);
    sum2 = a2+b2;
    printf("a2 + b2 = %f\n", sum2);

    printf("enter two real numbers, and I will print out their sum:\n");
    scanf("%lf %lf", &a3, &b3);
    sum3 = a3+b3;
    printf("a3 + b3 = %lf\n", sum3);
}