Thread: Calculating a BIG number

The problem is I cant get the correct answer to the product of 3 numbers each over 1000. The answer is always wrong.

My compiler is Borland C++ 3.1 and my code is supplied.

What can I do to get the answer of 3375000000 when 1500 is multiplyed by 1500 and then multiplyed by 1500 again.

Here is the code

#include <stdio.h>

int main (void)
{
long int a,b,c,d;

printf("Enter 1st number over 1000?");
scanf("%d",&a);

printf("Enter 2nd number over 1000?");
scanf("%d",&b);

printf("Enter 3rd number over 1000?");
scanf("%d",&c);

d = (a*b*c);

printf("The product of the 3 numbers is %d",d);

return 0;
}