#include<stdio.h>

float addf(a,b);

    int main(){

        float input1 = 10.0;
        float input2 = 20.0;

        printf("%f + %f = %f", input1, input2, addf(input1, input2) );

        getchar();

        return 0;
    }

float addf(float a, float b){

    return a + b;
}