#include <stdio.h>

int nextDigit ( int r , int s , int grp )
{
   int d = 0;

   /* Keep on searching for the next digit in the square root */
   while ((20*s+d)*d <= 100*r+grp) ++d;
   /* Here d is just one bigger than the correct digit */
   return(d-1);
}

void printSqrt ( int n )
{
   int s,       /* Square root found so far */
       r,       /* Whatever remains */
       d,       /* next digit */
       nl,      /* Number of digits to the left of the decimal point */
       nr = 3,  /* Number of digits to the right of the decimal point */
       grp[8],  /* 2-digit groups */
       sgn,     /* Sign of n */
       i;       /* An index */

   if (n < 0) { sgn = 1; n = -n; } else sgn = 0;
   if (n == 0) { nl = 1; grp[0] = 0; }
   else {
      nl = 0;
      while (n != 0) {
         grp[nl] = n % 100;  /* Save next 2-digit group */
         n /= 100;
         ++nl;
      }
   }

   /* Initialize */
   s = 0; r = 0;

   /* First print the digits to the left of the decimal point */
   for (i=nl-1; i>=0; --i) {
      d = nextDigit(r,s,grp[i]);
      printf("%d",d);
      r = (100 * r + grp[i]) - (20 * s + d) * d;
      s = 10 * s + d;
   }

   /* Print the decimal point */
   printf(".");

   /* Print digits after the decimal point */
   for (i=0; i<nr; ++i) {
      d = nextDigit(r,s,0);
      printf("%d",d);
      r = 100 * r - (20 * s + d) * d;
      s = 10 * s + d;
   }

   /* Square root of negative numbers should be imaginary */
   if (sgn) printf("i");

   printf("\n");
}

int main ()
{
   int n;

   printf("Enter an integer : ");
   scanf("%d",&n);
   printSqrt(n);
}