#include <iostream>
#include <vector>
#include <list>
#include <map>
#include <algorithm>
#include <string>
#include <cstring>
using namespace std;
#define endl '\n'
#define int long long 
#define IOS ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
typedef unsigned long long ull ;
typedef long long ll ;
typedef pair<int, int>PII;

void solve(){
   int n;
   cin>>n;
   if(n<10) {
      cout<<n+1;
      return ;
   }
   if(n==10){
      cout<<10;
      return ;
   }

//计算位数算法需优化
   int x = n;
   int a = 1, b = 1;
   int t = 1;
   while(x/10){
      a=x/10;
      t++;
      if(x/100==0&&x/10!=0){
         b=x%10;
      }
      x/=10;
   }

   int ans;
   if(a<=b) ans = a*t+(10-a)*(t-1);
   else ans = (a-1)*t+(11-a)*(t-1);
   cout<<ans;
}

signed main(){
   IOS;
   int tt;
   tt=1;
   //cin>>tt;
   while(tt--)
      solve();
   return 0;
}