func_code_string: #include <bits/stdc++.h>   using namespace std;   int32_t main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     string s;     cin >> s;     long long n = s.length();     vector<long long> prefix(n + 1, 0);     for (long long i = 1; i <= n; i++) {       if (isupper(s[i - 1]))         prefix[i] = prefix[i - 1] + 1;       else         prefix[i] = prefix[i - 1];     }     long long ans = LLONG_MAX;     for (long long i = 0; i <= n; i++) {       long long up = i - prefix[i];       long long down = prefix[n] - prefix[i];       ans = min(ans, up + down);     }     cout << ans << endl;     return 0;   }   