#include<bits/stdc++.h>
using namespace std;
using ll = long long ;

string s;
ll dp[100][2][2][10];
ll calc(int ind, bool less, bool mid, int dig) {
    if(ind==(int)s.size()) return 1;
    if(dp[ind][less][mid][dig]!=-1) return dp[ind][less][mid][dig];
    ll ans=0;
    for(int i=0;i<10;++i) {
        if(!mid && (less || i<=s[ind]-'0')) {
            ans+=calc(ind+1, less|(i<s[ind]-'0'), dig>i, i);
        }
        if(mid && (less || i<=s[ind]-'0') && dig>=i) {
            ans+=calc(ind+1, less|(i<s[ind]-'0'), mid, i);
        }
    }
    return dp[ind][less][mid][dig]=ans;
}

int main() {
    cin>>s;
    memset(dp, -1, sizeof dp);
    
    bool is=false;
    for(int i=0;!is&&i<(int)s.size();++i) {
        bool ok=true;
        for(int j=1;j<=i;j++) {
            ok&=s[j]>=s[j-1];
        }
        for(int j=i+1;j<(int)s.size();++j) {
            ok&=s[j]<=s[j-1];
        }
        is|=ok;
    }    

    cout<<calc(0, 0, 0, 0)-is<<"\n";
}