#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for(int i=a; i<n; i++)
#define repq(i,a,n) for(int i=a; i<=n; i++)
#define repr(i,a,n) for(int i=a; i>=n; i--)
typedef long long int ll;
typedef pair<int, int> pii;
template<typename T> void chmax(T &a, T b) {a = max(a, b);}
template<typename T> void chmin(T &a, T b) {a = min(a, b);}

// digit, mod, has3, flag
ll dp[25][3][2][2];

int main() {
    int n; cin >> n;
    string s(n, '0');
    s = '1' + s;

    int m = s.length();
    dp[0][0][0][0] = 1;
    rep(i,0,m) rep(j,0,3) rep(k,0,2) rep(l,0,2) {
        int lim = (l == 1 ? 9 : s[i] - '0');
        rep(x,0,lim + 1) {
            int mo = (j + x) % 3;
            dp[i+1][mo][k || (x == 3)][l || x < lim] += dp[i][j][k][l];
        }
    }

    ll ans = 0;
    rep(j,0,3) rep(k,0,2) rep(l,0,2) {
        if(j == 0 || k == 1) ans += dp[m][j][k][l];
    }
    cout << ans - 1 << endl;
    return 0;
}