#include <cstdio>
const int mod = 1e9+7;
char s[100005];
int f[100005][10][2];
// f[i][j][k]: i chac, now len is j, used/not
int rnk[28];

int main(){
	int n;
	scanf("%d%s",&n,s+1);
	f[0][0][0] = 1;
	int len = 9;
	char a[] = "yukicoder";
	for(int i = 0; i < 26; i++){
		char cur = 'a' + i;
		rnk[i] = -1;
		for(int j = 0; j < 9; j++){
			if(cur == a[j]) rnk[i] = j+1;
		}
	}
	for(int i = 1; i <= n; i++){
		for(int j = 0; j <= len; j++){
			for(int k = 0; k < 2; k++){
				f[i][j][k] = f[i-1][j][k];
				if(k && s[i]=='?' && j) f[i][j][k] = (f[i][j][k] + f[i-1][j-1][0])%mod;
				if(s[i]!='?'){
					int cur = s[i]-'a';
					if(rnk[cur]!=-1){
						int jj = rnk[cur];
						if(jj == j) f[i][j][k] = (f[i][j][k] + f[i-1][j-1][k])%mod;
					}
				}
				//printf("f[%d][%d][%d] = %lld\n",i,j,k,f[i][j][k]);
			}
			
		}
	}
	printf("%d\n",(f[n][9][0] + f[n][9][1])%mod);
	return 0;
}