N = int(input())

Q = N // 2
R = N % 2
MaxNum = 0

if R == 1:
    for i in range(Q - 1):
        MaxNum += 10**i
    MaxNum += 7 * 10**(Q - 1)
else:
    for i in range(Q):
        MaxNum += 10**i

print(MaxNum)