#include<bits/stdc++.h>
using namespace std;
#define int long long
#define lb long double
const int Max = 2*(int)1e3,mod = 998244353;
int f[2][130][10],presum[10],sum[10],invaild[10];
void solve() {
    int n;cin >> n;
    string s;cin >> s;
    s = " "+ s;
    int t = 0;
    sum[0] = 1;
    for(int i = 1; i <= n; i++,t = 1-t) {
        for(int j = 0; j < 8; j++)presum[j] = sum[j]%mod,sum[j] = 0;
        if((s[i]>='A'&&s[i]<='Z')) {
            for(int k = 0; k <= 128; k++)
                for(int j = 1; j <= 8; j++)f[t][k][j] = 0;
            invaild[0] = 1,invaild[1] = 1,invaild[2] = 1,invaild[3] = 1;
            if(!invaild[4])f[t][s[i]][4] = (presum[0]-f[1-t][s[i]][0]+presum[4]-f[1-t][s[i]][4])%mod,sum[4] += f[t][s[i]][4];
            if(!invaild[5])f[t][s[i]][5] = (presum[1]-f[1-t][s[i]][1]+presum[5]-f[1-t][s[i]][5])%mod,sum[5] += f[t][s[i]][5];
            if(!invaild[6])f[t][s[i]][6] = (presum[2]-f[1-t][s[i]][2]+presum[6]-f[1-t][s[i]][6])%mod,sum[6] += f[t][s[i]][6];
            if(!invaild[7])f[t][s[i]][7] = (presum[3]-f[1-t][s[i]][3]+presum[7]-f[1-t][s[i]][7])%mod,sum[7] += f[t][s[i]][7];
            continue;
        }
        if((s[i]>='0'&&s[i]<='9')) {
            for(int i = 0; i <= 128; i++)
                for(int j = 1; j <= 8; j++)f[t][i][j] = 0;
            invaild[0] = 1,invaild[2] = 1,invaild[4] = 1,invaild[6] = 1;
            if(!invaild[1])f[t][s[i]][1] = (presum[0]-f[1-t][s[i]][0]+presum[1]-f[1-t][s[i]][1])%mod,sum[1] += f[t][s[i]][1];
            if(!invaild[3])f[t][s[i]][3] = (presum[2]-f[1-t][s[i]][2]+presum[3]-f[1-t][s[i]][3])%mod,sum[3] += f[t][s[i]][3];
            if(!invaild[5])f[t][s[i]][5] = (presum[4]-f[1-t][s[i]][4]+presum[5]-f[1-t][s[i]][5])%mod,sum[5] += f[t][s[i]][5];
            if(!invaild[7])f[t][s[i]][7] = (presum[6]-f[1-t][s[i]][6]+presum[7]-f[1-t][s[i]][7])%mod,sum[7] += f[t][s[i]][7];
            continue;
        }
        if((s[i]>='a'&&s[i]<='z')) {
            for(int i = 0; i <= 128; i++)
                for(int j = 1; j <= 8; j++)f[t][i][j] = 0;
            invaild[0] = 1,invaild[1] = 1;
            if(!invaild[2])f[t][s[i]][2] = (presum[0]-f[1-t][s[i]][0]+presum[2]-f[1-t][s[i]][2])%mod,sum[2] += f[t][s[i]][2];
            if(!invaild[3])f[t][s[i]][3] = (presum[1]-f[1-t][s[i]][1]+presum[3]-f[1-t][s[i]][3])%mod,sum[3] += f[t][s[i]][3];
            if(!invaild[6])f[t][s[i]][6] = (presum[4]-f[1-t][s[i]][4]+presum[6]-f[1-t][s[i]][6])%mod,sum[6] += f[t][s[i]][6];
            if(!invaild[7])f[t][s[i]][7] = (presum[5]-f[1-t][s[i]][5]+presum[7]-f[1-t][s[i]][7])%mod,sum[7] += f[t][s[i]][7];
            s[i] = s[i]-'a'+'A';
            if(!invaild[4])f[t][s[i]][4] = (presum[0]-f[1-t][s[i]][0]+presum[4]-f[1-t][s[i]][4])%mod,sum[4] += f[t][s[i]][4];
            if(!invaild[5])f[t][s[i]][5] = (presum[1]-f[1-t][s[i]][1]+presum[5]-f[1-t][s[i]][5])%mod,sum[5] += f[t][s[i]][5];
            if(!invaild[6])f[t][s[i]][6] = (presum[2]-f[1-t][s[i]][2]+presum[6]-f[1-t][s[i]][6])%mod,sum[6] += f[t][s[i]][6];
            if(!invaild[7])f[t][s[i]][7] = (presum[3]-f[1-t][s[i]][3]+presum[7]-f[1-t][s[i]][7])%mod,sum[7] += f[t][s[i]][7];
            continue;
        }
        for(s[i] = (int)'0'; (int)s[i] < 127; s[i] = (char)(s[i]+1)) {
            if((s[i]>='A'&&s[i]<='Z')) {
                if(!invaild[4])f[t][s[i]][4] = (presum[0]-f[1-t][s[i]][0]+presum[4]-f[1-t][s[i]][4])%mod,sum[4] += f[t][s[i]][4];
                if(!invaild[5])f[t][s[i]][5] = (presum[1]-f[1-t][s[i]][1]+presum[5]-f[1-t][s[i]][5])%mod,sum[5] += f[t][s[i]][5];
                if(!invaild[6])f[t][s[i]][6] = (presum[2]-f[1-t][s[i]][2]+presum[6]-f[1-t][s[i]][6])%mod,sum[6] += f[t][s[i]][6];
                if(!invaild[7])f[t][s[i]][7] = (presum[3]-f[1-t][s[i]][3]+presum[7]-f[1-t][s[i]][7])%mod,sum[7] += f[t][s[i]][7];
                continue;
            }
            if((s[i]>='0'&&s[i]<='9')) {
                if(!invaild[1])f[t][s[i]][1] = (presum[0]-f[1-t][s[i]][0]+presum[1]-f[1-t][s[i]][1])%mod,sum[1] += f[t][s[i]][1];
                if(!invaild[3])f[t][s[i]][3] = (presum[2]-f[1-t][s[i]][2]+presum[3]-f[1-t][s[i]][3])%mod,sum[3] += f[t][s[i]][3];
                if(!invaild[5])f[t][s[i]][5] = (presum[4]-f[1-t][s[i]][4]+presum[5]-f[1-t][s[i]][5])%mod,sum[5] += f[t][s[i]][5];
                if(!invaild[7])f[t][s[i]][7] = (presum[6]-f[1-t][s[i]][6]+presum[7]-f[1-t][s[i]][7])%mod,sum[7] += f[t][s[i]][7];
                continue;
            }
            if((s[i]>='a'&&s[i]<='z')) {
                if(!invaild[2])f[t][s[i]][2] = (presum[0]-f[1-t][s[i]][0]+presum[2]-f[1-t][s[i]][2])%mod,sum[2] += f[t][s[i]][2];
                if(!invaild[3])f[t][s[i]][3] = (presum[1]-f[1-t][s[i]][1]+presum[3]-f[1-t][s[i]][3])%mod,sum[3] += f[t][s[i]][3];
                if(!invaild[6])f[t][s[i]][6] = (presum[4]-f[1-t][s[i]][4]+presum[6]-f[1-t][s[i]][6])%mod,sum[6] += f[t][s[i]][6];
                if(!invaild[7])f[t][s[i]][7] = (presum[5]-f[1-t][s[i]][5]+presum[7]-f[1-t][s[i]][7])%mod,sum[7] += f[t][s[i]][7];

            }
        }

    }
    cout << sum[7];
}
 signed main() {
#ifdef ACM_LOCAL
    freopen("data.in","r",stdin);
    freopen("data.out","w",stdout);
#endif
    ios::sync_with_stdio(0);
    cin.tie(0);
    int t=1;
    //cin>>t;
    while(t--) {
        solve();
    }
}