// TLE if N is large

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

bool is_nabeatsu(string N){
    int digitsum = 0;
    for (char c:N) digitsum += c - '0';
    return digitsum % 3 ==0 || find(N.begin(), N.end(), '3') != N.end();
}

int main(){
    string N;
    cin >> N;

    assert(N.size() <= 1000000 || N == "1" + string(1000000, '0'));
    assert(N[0] != '0');

    while (is_nabeatsu(N)){
        for (int i = N.size() - 1;; i--){
            if (N[i] == '0') N[i] = '9';
            else{
                N[i]--;
                break;
            }
        }
    }
    cout << N << endl;
    return 0;
}