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

#define FOR(i,l,r) for(int i = (int) (l);i < (int) (r);i++)
#define ALL(x) x.begin(),x.end()
template<typename T> bool chmax(T& a,const T& b){ return a < b ? (a = b,true) : false; }
template<typename T> bool chmin(T& a,const T& b){ return b < a ? (a = b,true) : false; }
typedef long long ll;

string S("yukicoder");
string T;

int main()
{
	cin >> T;
	FOR(i,0,T.size()){
		if(T [i] != S [i]){
			cout << S [i] << endl;
			break;
		}
	}

	return 0;
}