A program to explain FUNCTION PROTOTYPE

#include <stdio.h>
 
int area(int, int);
 
void main()
{
    int l, b, ar;
    printf("Enter l, b: ");
    scanf("%d %d", &l, &b);
    ar = area(l, b);
    printf("Area = %d", ar);
 
    printf("\n");
}
 
int area(int p, int q)
{
    int a;
    a = p * q;
    return a;
}