inputs = []
input_line = input().split()
for i in input_line:
    inputs.append(int(i))

sum = 0
syou = int(inputs[0] / 2)
amari = int(inputs[0] % 2)

for i in range(syou):
    sum += 10**i
if amari == 1:
    sum += 6 * 10 ** (syou - 1)
print(sum)