#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 ILL=1167167167167167167;
const int INF=2100000000;
const ll mod=1e9+7;
#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;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}



//  rainy ~ 雨に打たれて ~
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int N;
	cin>>N;
	string S;
	cin>>S;
	string T="yukicoder";
	int M=9;
	vector<int> dp1(N+1),dp2(N+1);
	dp1[0]=1;
	rep(i,N){
		if(S[i]=='?'){
			rep(k,N){
				dp2[k+1]=(dp2[k+1]+dp1[k])%mod;
			}
		}
		rep(j,M){
			if(S[i]==T[j]){
				dp1[j+1]=(dp1[j]+dp1[j+1])%mod;
				dp2[j+1]=(dp2[j]+dp2[j+1])%mod;
			}
		}
	}
	cout<<(dp1[M]+dp2[M])%mod<<"\n";
}