#include <stdio.h>

void input (int *a, int *b, int *c);
void average (int *a, int *b, int *c, float *avg_val);
void output (float calc_avg);

void main()
{
    int a,b,c;
    float avg_val;
    
    input (&a, &b, &c);
        
    average(&a, &b, &c, &avg_val);
    output(avg_val);
}

void input (int *a, int *b, int *c)
{
    printf("\n\nPlease enter three integers: ");
    scanf("%d %d %d", a, b, c);
}
    
void average (int *a, int *b, int *c, float *avg_val)
{
    *avg_val=(float)(*a + *b + *c)/3.0;
}
    
void output (float calc_avg)
{
    printf("\n\nThe average of the three values is: %f\n\n", calc_avg);
}