n = int(input())
t = []
for i in range(1, 10):
	for j in range(i+1, 10):
		t.append((i, j))

n -= 1
v = n // 36
w = n % 36

g = [str(t[w][0]), str(t[w][1])]
for i in range(v):
	g.append(str(t[w][1]))
print("".join(g))