#include<bits/stdc++.h>
using namespace std;
using ll=long long;
const int N=1e5+10,mod=998244353;
int n,f[2][8][26+26+10];
char a[N];
int trans(char c){
    if(isdigit(c))return c-'0';
    else if(islower(c))return c-'a'+10;
    else return c-'A'+10+26;
}
int get(int i){
    if(i<10)return 0;
    if(i<10+26)return 1;
    return 2;
}
vector<int>p[128];
int main(){
    scanf("%d%s",&n,a+1);
    for(int i=0;i<26;i++){
        p['a'+i]={trans('a'+i),trans('A'+i)};
        p['A'+i]={trans('A'+i)};
        p['?'].push_back(trans('a'+i));
        p['?'].push_back(trans('A'+i));
    }
    for(int i=0;i<10;i++){
        p['0'+i]={trans('0'+i)};
        p['?'].push_back(trans('0'+i));
    }
    // cerr<<p['?'].size()<<endl;
    int now=1,las=0;
    for(int x:p[a[1]])f[now][1<<get(x)][x]=1;
    for(int i=2;i<=n;i++){
        swap(now,las),memset(f[now],0,sizeof f[now]);
        static int sum[8];
        memset(sum,0,sizeof sum);
        for(int S=1;S<8;S++){
            for(int x=0;x<10+26+26;x++){
                (sum[S]+=f[las][S][x])%=mod;
            }
        }
        for(int S=1;S<8;S++){
            for(int y:p[a[i]]){
                (f[now][S|1<<get(y)][y]+=(sum[S]-f[las][S][y]+mod)%mod)%=mod;
            }
        }
    }
    int ans=0;
    for(int x:p['?'])(ans+=f[now][7][x])%=mod;
    cout<<ans<<endl;
    return 0;
}