#include<stdio.h>
void main()
{
    int a,b,t;
    printf("Input two numbers\n");                             
    scanf("%d%d",&a,&b);
    if(a>b)
    {  
        while(b!=0)
        {
            t=b;
            b=a%b;
            a=t;
              }
     printf("gcd=%d\n",a);
   ...