a#include<bits/stdc++.h> using namespace std; int main(){ int n=1,m=0,ans=0; while(n!=0){ cin>>n; if(n==3){ ans++; } if(n+1==3) ans++; if(n>3){ while(n<=100){ m=n/3,ans+=m; n=n%10; n+=ans; } if(n+1==3){ ans++; } } cout<<ans<<endl; } return 0; }