n = int(input())
if n % 2 == 0:
    x = int(n / 2)
    ans = 0
    for i in range(1, x + 1):
        ans += 10**(x - i)
else:
    ans = 0
    if n == 1:
        pass
    else:
        x = int(n // 2)
        y = int(n % 2)
        ans = 7 * 10 ** (x-1)
        for i in range(1, x):
            ans += 10 ** ((x-1) -i)

print(ans)