#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cassert>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    string s; cin >> s;
    int n = s.size();
    vector<int> ord(n);
    auto ok = [&](){
        for(int i = 0; i < n; i++){
            if(ord[i] == 0 && s[i] != '?') return false;
        }
        return true;
    };

    for(int j = 1; !ok(); j++){
        vector<bool> appear(26);
        for(int i = n-1; i >= 0; i--){
            if(s[i] == '?') continue;
            if(ord[i] != 0) continue;
            bool f = true;
            for(int k = s[i]-'a'+1; k < 26; k++){
                if(appear[k]) f = false;
            }
            if(f) ord[i] = j;
            appear[s[i]-'a'] = true;
        }
    }

    vector<int> v;
    int mx = *max_element(ord.begin(), ord.end());
    if(mx == 0) mx = 1;
    for(int i = 0; i < n; i++){
        if(ord[i] == mx) v.push_back(i);
    }
    for(int i = 0; i < n; i++){
        if(s[i] == '?'){
            auto p = lower_bound(v.begin(), v.end(), i);
            if(p == v.end()) s[i] = 'a';
            else s[i] = s[*p];
        }
    }
    cout << s << endl;
}