# -*- coding: utf-8 -*-

def solve(n):
    result = 0
    if n % 2 == 0:
        for i in range(0, n // 2):
            result += (10 ** i)
    else:
        for i in range(0, n // 2):
            result += (10 ** i) if i < (n // 2) - 1 else 7 * (10 ** i)
    print(result)

n = int(input())
solve(n)