#include<bits/stdc++.h> #include<atcoder/all> using namespace std; using namespace atcoder; #define rep(i,n)for (int i = 0; i < int(n); ++i) #define rrep(i,n)for (int i = int(n)-1; i >= 0; --i) #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() template<class T> void chmax(T& a, const T& b) {a = max(a, b);} template<class T> void chmin(T& a, const T& b) {a = min(a, b);} using ll = long long; using P = pair<int,int>; using VI = vector<int>; using VVI = vector<VI>; using VL = vector<ll>; using VVL = vector<VL>; using mint = modint1000000007; const string yuki = "yukicoder"; int main() { ios::sync_with_stdio(false); cin.tie(0); int n; cin >> n; string s; cin >> s; mint dp[yuki.size() + 1][2] = {}; dp[0][0] = 1; for(char c: s) { rrep(j, yuki.size()) rep(k, 2) { if (c == '?') { if (k) continue; dp[j + 1][1] += dp[j][0]; } else if (yuki[j] == c) { dp[j + 1][k] +=dp[j][k]; } } } mint ans; rep(k, 2) ans += dp[yuki.size()][k]; cout << ans.val() << endl; }