1. 0
2. trei valori: 1, 12 si 123
3.#include <bits/stdc++.h>
using namespace std;
int main(){
int n,k,c,naux;
scanf("%d",&n);
k=0;
c=0;
naux=n;
while(naux>0){
naux=naux/10;
k=k+1;
c=c*10+1;
}
for(int i=1;i<=k;++i){
n=n-c;
c=c/10;
}
printf("%d",n);
return 0;
}
