#include<stdio.h>

 struct s{
 int x;
 int y;
 };

 int main(void)
 {
 struct s a={10,20};
 struct s b={10,20};
 struct s c={30,40};

 if(a.x==b.x)a.x=c.x;
 printf("a.x = %d\n",a.x);

 a=b;

 //if(a ==b)a=c;
 printf("a.y = %d\n",a.y);

 return 0;
 }