Submission #1778782

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Source Code Expand

#include <bits/stdc++.h>
#define FOR(k,m,n) for(int(k)=(m);(k)<(n);(k)++)
#define REP(k,n) FOR((k),0,(n))
using namespace std;
typedef long long ll;
typedef vector<ll> VLL;
const int MOD=1000000007;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    string s(100000, '\0');
    cin >> s;
    FOR(i, 0, 26){
        if (s.find('a'+i) != -1){
            continue;
        }
        char res = 'a' + i;
        cout << res << endl;
        return 0;
    }

    cout << "None" << endl;

    return 0;
}

Submission Info

Judge Result