#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include<iostream>
using namespace std;
#include<atcoder/all>
using mint=atcoder::modint1000000007;

mint dp[2][10];
string s,t="yukicoder";
int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin>>s>>s;
  dp[0][0]=1;
  for(auto x:s){
    if(x=='?'){
      for(unsigned int j=0;j<9;++j)dp[1][j+1]+=dp[0][j];
    }else{
      unsigned int j=t.find(x);
      if(j<9){
        dp[0][j+1]+=dp[0][j];
        dp[1][j+1]+=dp[1][j];
      }
    }
  }
  cout<<(dp[0][9]+dp[1][9]).val()<<'\n';
}