#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define _GLIBCXX_DEBUG
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
ll I=1167167167167167167;
ll mod=998244353;
#define rep(i,a) for (ll i=0;i<a;i++)
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
template<class T> void print_tate(vector<T> &v) {rep(i,v.size()) cout<<v[i]<<"\n";}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}



//おちこんだりもしたけれど、私はげんきです。
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int N;
	string S;
	cin>>S;
	N=S.size();
	vector<char> p;
	for(int i=N-1;i>=0;i--){
		if(S[i]=='?') continue;
		int l=-1,r=p.size();
		while(r-l>1){
			int D=(r+l)/2;
			if(p[D]>S[i]) l=D;
			else r=D;
		}
		if(r==(int)p.size()) p.push_back(S[i]);
		else p[r]=S[i];
	}
	if(p.size()==0){
		rep(i,N) cout<<'a';
		cout<<"\n";
		return 0;
	}
	vector<char> q((int)p.size(),'a');
	for(int i=N-1;i>=0;i--){
		if(S[i]=='?'){
			S[i]='a';
		}
		int l=-1,r=p.size();
		while(r-l>1){
			int D=(r+l)/2;
			if(q[D]>S[i]) l=D;
			else r=D;
		}
		if(r==q.size()) S[i]=q[(int)q.size()-1];
		else q[r]=S[i];
	}
	cout<<S<<"\n";
	return 0;
}