n = int(input())
n -= 1
c, b = divmod(n, 9 * 8 // 2)
a = 0
while b - (8 - a) >= 0:
    b -= 8 - a
    a += 1

a += 1
b += a + 1
ans = str(10 * a + b) + str(b) * c
print(ans)