#include <stdio.h>
struct square{
    int a,b;
};
int main()
  {
      struct square base;
      scanf("%d",&base.a);
      if(unit.a<=0 ||base.a>1000){
          printf("Invalid input");
      }
     else{
         base.a=(long long) base.a *base.a;
     }
     return 0;
  }