#!/usr/bin/env python3.8
# %%
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
from functools import lru_cache


# %%
@lru_cache(None)
def f(N, i):
    """1以上N以下のうち、3と5のみからなり、mod 3 で i のものを数える"""
    if N < 10:
        if N >= 3 and i == 0:
            return 1
        if N >= 5 and i == 2:
            return 1
        return 0
    ret = 0
    if i in [0, 2]:
        ret = 1
    ret += f((N - 3) // 10, i)
    ret += f((N - 5) // 10, (i - 5) % 3)
    return ret


def cnt_super_fz(N):
    return f((N - 5) // 10, 1)


def solve(K):
    left = 0
    right = 10 ** 50
    while left + 1 < right:
        x = (left + right) // 2
        if cnt_super_fz(x) >= K:
            right = x
        else:
            left = x
    return right


# %%
print(solve(int(read())))