#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include<iostream>
using namespace std;
constexpr unsigned int mod=1000000007;
unsigned int dp[2][10];
constexpr char* t="yukicoder";
string s;
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];
        if(dp[1][j+1]>=mod)dp[1][j+1]-=mod;
      }
    }else{
      for(unsigned int j=0;j<9;++j){
        if(x==t[j]){
          dp[0][j+1]+=dp[0][j];
          if(dp[0][j+1]>=mod)dp[0][j+1]-=mod;
          dp[1][j+1]+=dp[1][j];
          if(dp[1][j+1]>=mod)dp[1][j+1]-=mod;
        }
      }
    }
  }
  unsigned int ans=dp[0][9]+dp[1][9];
  if(ans>=mod)ans-=mod;
  cout<<ans<<'\n';
}