#include<bits/stdc++.h>
using namespace std;
#include<atcoder/modint>
// #define int long long
using mint =atcoder::modint998244353;
signed main(){
    int n;cin>>n;
    string s;cin>>s;
    vector<mint>dp(n+1,0);
    dp[0]=1;
    for(int i=0;i<n;i++){
        for(int k=1;k<n/10+10;k++){
            if (i+k*10>=n+1)continue;
            if(s[i+2*k]=='o' && s[i+3*k]=='o' && s[i+5*k]=='o')dp[i+10*k]+=dp[i];
        }    
    }
    cout<<dp[n].val()<<endl;
}