#include <stdio.h>
#include <math.h>
main()
{
    int a=0;
    float b=0;
    while (!feof(stdin))
{
   scanf("%d", &a);
   b=sqrt(a);
   if (feof(stdin))
   printf("%.4f\n",b);

}
}


It works fine at my PC. But it keeps saying wrong answer?

#include <stdio.h>
#include <math.h>
main()
{
    int a=0;
    float b=0;
    while (!feof(stdin))
{
   scanf("%d", &a);
   b=sqrt(a);
   printf("%.4f\n",b);
}
}

You should use a long long data type, because the int type supports only 2^32 as max. Please, read the contraints of the problem. There says that the number could be as big as 10^18 (a lot bigger than 2^32). Try with long long. Hope it be useful for you.