Write a C program to find the greatest common divisor of the two given positive integers

#include< stido.h>
#include< conio.h>
int main( )
{
int a, b, res;
clrscr( );
printf("Enter the two integer values:");
scanf("%d%d", &a, &b);

for(  ;  ;  )                                                  //This is empty for loop.
{
res = a%b;
if( res = = 0) break;
a = b;
b = res;
}
printf("\n The GCF is : %d", res);
getch( );
return 0;
}