N = int(input())
N -= 1
ls = []
for a in range(8):
    for b in range(a + 1, 9):
        ls.append((a + 1, b + 1))
L = len(ls)
a, b = ls[N % L]
ans = 10 * a + b
for _ in range(N // L):
    ans = ans * 10 + b
print(ans)