p= int(input())
s= str(10**p)
dp=[[[[0]*3 for _ in range(2)] for _ in range(2)] for _ in range(p+1+1)]
dp[0][0][0][0]=1 # dp[桁][未満][3がつく][%3剰余]
for i in range(p+1):
    for j in range(2):
        for d in range(10 if j==1 else int(s[i])):
            for k in range(2):
                for l in range(3):
                    dp[i+1][j|(d<int(s[i]))][k|(d==3)][(10*l+d)%3]+=dp[i][j][k][l]
print(dp[-1][1][0][0]+sum(dp[-1][1][1])-1)