#include "library.h"

int sqroot(const int square, const int first, const int last)
{ if (first > last)
    return -1;
  const int middle = (first + last) / 2;
  const int seen = middle * middle;
  if (seen == square)
    return middle;
  if (seen < square)
    return sqroot(square, middle + 1, last);
  else
    return sqroot(square, first, middle - 1); }

int sqroot(const int square)
{ return sqroot(square, 0, square + 1); }

void main()
{ cout << "Enter a number: ";
  const int number = read_int();
  const int root = sqroot(number);
  cout << "The square root is " << root << "\n";
  main(); }