func_code_string: #include <bits/stdc++.h>   using namespace std;   template <typename T>   void read(T &x) {     register T c = getchar();     x = 0;     int t = 0;     if (c ==  - ) t = 1, c = getchar();     for (; (c < 48 || c > 57); c = getchar())       ;     for (; c > 47 && c < 58; c = getchar()) {       x = (x << 1) + (x << 3) + c - 48;     }     if (t) x = -x;   }   int main() {     int n, Max = 0;     read(n);     string str;     cin >> str;     bool visited[250] = {0};     for (int i = 0; i < n; i++) {       if (str[i] >=  a  && !visited[i]) {         set<char> s;         visited[i] = 1;         s.insert(str[i]);         for (int j = i + 1; j < n; j++) {           if (str[j] <=  Z ) break;           visited[j] = 1;           s.insert(str[j]);         }         if (Max < s.size()) Max = s.size();       }     }     cout << Max;   }   