func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     const int N = 26;     int mas[26];     for (int i = 0; i < N; ++i) mas[i] = 0;     int rez = 0;     for (int i = 0; i < n * 2 - 2; ++i) {       char a;       cin >> a;       if (isupper(a)) {         if (mas[tolower(a) -  a ] > 0)           mas[tolower(a) -  a ]--;         else           rez++;       } else         mas[a -  a ]++;     }     cout << rez << endl;     return 0;   }   