import sys
input = sys.stdin.readline

N=int(input())

X=[]

for i in range(1,10):
    for j in range(i+1,10):
        X.append(i*10+j)


k=N//36
l=N%36

ANS=str(X[l-1])

for i in range(k):
    ANS+=ANS[-1]

if l==0:
    ANS=ANS[:-1]
print(ANS)