#include<bits/stdc++.h> using namespace std; int main(){ int n; cin>>n; long long ans=0; for(int i=1;i<=n;i++){ long long len1=0,len2=1,len3=0; len1=i; while(len1){ len2=len210; len3=len310+len1%10; len1=len1/10; } ans=ans+i*len2+len3; } cout<<ans; return 0; }