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

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    string s; cin >> s;
    while(true){
        bool ok = false;
        for(auto &c : s){
            if(ok) c = '9';
            
            else if(c == '3') ok = true,c--;
        }
        int sum = 0;
        for(auto c : s) sum += c-'0';
        if(sum%3) break;
        for(int i=s.size(); i--;){
            if(s.at(i) == '0') s.at(i) = '9';
            else{s.at(i)--; break;}
        }
    }
    while(s.size() && s.at(0) == '0') s.erase(s.begin());
    cout << s << endl;
}