#!/usr/bin/env python3

def sols():
    """yields int solutions of a**2 - 5 b**2 = 1"""
    a, b = 9, 4
    while True:
        yield a, b
        a, b = 9*a + 20*b, 4*a + 9*b

def Cs():
    """yields int solutions of a in a**2 - 5 b**2 = -4"""
    for a, b in sols():
        yield 25*b - 11*a
        yield 10*b - 4*a
        yield 5*b - a

gen = Cs()
next(gen)
count = 0

N = 15

while count < N:
    c = next(gen)
    if (c-1) % 5 != 0:
        continue
    count += 1

n = (c-1) // 5
print(n)