func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(false);     int n;     cin >> n;     string s;     cin >> s;     long long l = s.length();     bool visit[256];     memset(visit, false, sizeof(visit));     int dis = 0, i;     for (i = 0; i < l; i++) {       if (!visit[s[i]]) {         visit[s[i]] = true;         dis++;       }     }     if (dis == 1) {       cout << ((l * (l + 1)) / 2) % 998244353;       return 0;     }     int s_cnt = 1, e_cnt = 1;     i = 1;     int j = l - 2;     for (; i < l; i++) {       if (s[i] == s[0])         s_cnt++;       else         break;     }     for (; j >= 0; j--) {       if (s[j] == s[n - 1])         e_cnt++;       else         break;     }     if (s[0] != s[l - 1]) {       cout << (e_cnt + s_cnt + 1) % 998244353;     } else {       cout << (long long)((long long)(s_cnt + 1) % 998244353 *                           (long long)(e_cnt + 1) % 998244353) %                   998244353;     }     return 0;   }   