#include <bits/stdc++.h>
using namespace std;
int main(){
  string S;
  cin >> S;
  int N = S.size();
  string S2 = S;
  for (int i = N - 2; i >= 0; i--){
    if (S2[i] == '?' && S2[i + 1] != '?'){
      S2[i] = S2[i + 1];
    }
  }
  for (int i = 0; i < N; i++){
    if (S2[i] == '?'){
      S2[i] = 'a';
    }
  }
  vector<vector<char>> dp(N + 1, vector<char>(26, '`'));
  for (int i = N - 1; i >= 0; i--){
    dp[i] = dp[i + 1];
    for (int j = 0; j < 26; j++){
      if (dp[i][j] <= S2[i]){
        dp[i][j] = S2[i];
        break;
      }
    }
  }
  int L = 26;
  for (int i = 0; i < 26; i++){
    if (dp[0][i] == '`'){
      L = i;
      break;
    }
  }
  vector<char> dp2(26, '{');
  for (int i = 0; i < N; i++){
    for (int j = 0; j < 26; j++){
      char c = 'a' + j;
      bool ok = true;
      if (S[i] != '?' && S[i] != c){
        ok = false;
      } else {
        vector<char> dp3 = dp2;
        *lower_bound(dp3.begin(), dp3.end(), c) = c;
        for (int k = 0; k < L; k++){
          if (dp3[k] < dp[i + 1][L - k - 1]){
            ok = false;
          }
        }
      }
      if (ok){
        S[i] = c;
        *lower_bound(dp2.begin(), dp2.end(), c) = c;
      }
    }
  }
  cout << S << endl;
}