N = int(input())
match = {1: 0, 2: 1, 5: 5, 4: 4, 3: 7, 7: 8, 6: 9}
res = 0
i = 1
if N % 2 == 1 and N >= 3:
    res += 7
    N -= 3
elif N >= 4:
    res += 1
    N -= 2
else:
    res += match[N]
    N = 0
i *= 10
while N > 0:
    res *= i
    res += 1
    N -= 2
    i *= 10
print(res)