#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using V = vector<ll>;
using VV = vector<V>;
using VVV = vector<VV>;
using VS = vector<string>;
using P = pair<ll,ll>;
using M = map<ll,ll>;
using Q = queue<ll>;
using PQ = priority_queue<ll>;
using PQG = priority_queue<ll,V,greater<ll>>;
using S = set<ll>;
const ll MOD = 1000000007;
const ll Mod = 998244353;
const ll INF = 1LL << 60;
#define rep(i,n) for(ll i = 0; i < n; i++)
#define rep2(i,s,n) for(ll i = s; i < n; i++)
#define rep3(i,s,n) for(ll i = s; i <= n; i++)
#define all(x) (x).begin(),(x).end()
#define MP(a,b) make_pair(a,b)
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}
template<class T>void Vin(vector<T>&a){rep(i,(int)a.size())cin>>a[i];}
template<class T>void Vout(const vector<T>&a){rep(i,(int)a.size())cout<<a[i]<<endl;}
ll power(ll a,ll b,const ll&M){a%=M;ll res=1;while(b>0){if(b&1)res=res*a%M;a=a*a%M;b>>=1;}return res;}
const ll H[4] = {0,1,0,-1}, W[4] = {1,0,-1,0};

int main() {
    ll n, ans = 0;
    string s, t = "yukicoder";
    cin >> n >> s;
    VV dp(10,V(9));
    for(char c : s) {
        rep(i,9) if(c == t[i]) {
            rep(j,10) if(i != j) {
                if(i == 0) dp[j][i] = (dp[j][i] + 1) % MOD;
                else dp[j][i] = (dp[j][i] + dp[j][i-1]) % MOD;
            }
            break;
        }
        if(c == '?') rep(i,9) {
            if(i == 0) dp[i][i] = (dp[i][i] + 1) % MOD;
            else dp[i][i] = (dp[i][i] + dp[i][i-1]) % MOD;
        }
    }
    rep(i,10) ans = (ans + dp[i][8]) % MOD;
    cout << ans << endl;
}