#include <stdio.h>
    int subtract(int p, int q, int r)
    {
        return p - q - r;
    }
    void main()
    {
        int (*fun_ptr)(int, int, int);
        fun_ptr = &subtract;
        printf("The Subtraction of three numbers is : %d",
        (*fun_ptr)(21, 13, 41));
    }