func_code_string: #include <bits/stdc++.h>   using namespace std;   const int inf = 2e9 + 1e8;   const long long INF = 2e18 + 1e17;   const int mod = 998244353;   const int MOD = 1e9 + 7;   long long gcd(long long a, long long b) { return (b == 0 ? a : gcd(b, a % b)); }   bool is_prime(int x) {     if (x <= 1 || (x % 2 == 0 && x > 2)) return false;     for (int i = 3; i * i <= x; i += 2) {       if (!(x % i)) {         return false;       }     }     return true;   }   const int MAXN = 40010;   int N;   string str;   vector<int> arr;   int ans;   int main() {     cin >> N >> str;     arr.resize(N);     int sum = 0;     for (int i = 0; i < str.length(); i++) {       arr[i] = (str[i] ==  )  ? -1 : 1);       sum += arr[i];     }     if (sum != 0) {       cout <<  -1  << endl;       return 0;     }     int cur = 0, last = 0;     bool bad = false;     for (int i = 0; i < N; i++) {       cur += arr[i];       if (!bad && cur < 0) {         bad = true;         last = i;       } else if (cur == 0 && bad) {         ans += (i - last + 1);         bad = false;       }     }     cout << ans << endl;     return 0;   }   