#!/usr/bin/env python3

from math import sqrt

def main(d):
    mx = 0
    my = 0
    md = 0
    for cd in range(2, d + 1):
        x, y = diop(cd)
        #print("{} -> {}, {}".format(cd, x, y))
        if x > mx:
            mx = x
            my = y
            md = cd
    return md, mx, my

def diop(d):
    sol = []
    a, f = sq_frac(d)
    f.reverse()
    if len(f) == 0:
        return 0, 0
    for i in f:
        for j in range(len(sol)):
            sol[j][0], sol[j][1] = sol[j][0] * i + sol[j][1], sol[j][0]
        sol.append([i, 1])
    r = fits(a, sol, d)
    while r == 0:
        for i in f:
            for j in range(len(sol)):
                sol[j][0], sol[j][1] = sol[j][0] * i + sol[j][1], sol[j][0]
        r = fits(a, sol, d)
    return r

def fits(a, pairs, d):
    for x, y in pairs[::-1]:
        x, y = a * x + y, x
        if x**2 - d * y**2 == 1:
            return x, y
    return 0

def sq_frac(x):
    f = []
    m = int(sqrt(x))
    if m**2 == x:
        return m, f
    d = x - m**2
    f.append((2 * m) // d)
    n = f[-1] * d - m
    while d != 1:
        d = (x - n**2) // d
        f.append((n + m) // d)
        n = f[-1] * d - n
    return m, f

if __name__ == '__main__':
    print(main(1000)[0])