# Principled Programming / Tim Teitelbaum / Chapter 1.

def main() -> None:
            """Output the Integer Square Root of an integer input."""
    # Obtain an integer n≥0 from the user.
            n: int = int(input("Enter integer:"))
    # Given n≥0, output the Integer Square Root of n.
        # Let r be the integer part of the square root of n≥0.
            r: int = 0
            while (r + 1) * (r + 1) <= n:
                r += 1
        # Output r.
            print(r)
main()