Language: C++

#include <iostream>
#include <cmath>                                                                                                                                                                                                    using namespace std;                                                                                                                                                                                                                                                                                                                                                                                                                    int main() {                                                                                                                                                                                                            string s, t;                                                                                                                                                                                                        cin >> s;
    cin >> t;
    int max = 0;
    for(int i=0; i<s.length() - t.length() + 1; i++) {
        int c = 0;
        for(int j=0; j<t.length(); j++) {
            if(s[i+j] == t[j]) {
                c++;
            }
        }
        if(max < c) max = c;
    }
    cout << t.length() - max << '\n';
    return 0;
}

Compiler output:
a.cc:2:213: warning: extra tokens at end of #include directive
    2 | #include <cmath>                                                                                                                                                                                                    using namespace std;                                                                                                                                                                                                                                                                                                                                                                                                                    int main() {                                                                                                                                                                                                            string s, t;                                                                                                                                                                                                        cin >> s;
      |                                                                                                                                                                                                                     ^~~~~
a.cc:2:5: error: 'cin' does not name a type
    2 | #include <cmath>                                                                                                                                                                                                    using namespace std;                                                                                                                                                                                                                                                                                                                                                                                                                    int main() {                                                                                                                                                                                                            string s, t;                                                                                                                                                                                                        cin >> s;
      |     ^~~
a.cc:4:5: error: expected unqualified-id before 'for'
    4 |     int max = 0;
      |     ^~~
a.cc:4:18: error: 'i' does not name a type
    4 |     int max = 0;
      |                  ^
a.cc:4:49: error: 'i' does not name a type
    4 |     int max = 0;
      |                                                 ^
a.cc:13:5: error: 'cout' does not name a type
   13 |     }
      |     ^   
a.cc:14:5: error: expected unqualified-id before 'return'
   14 |     cout << t.length() - max << '\n';
      |     ^~~~~~
a.cc:15:1: error: expected declaration before '}' token
   15 |     return 0;
      | ^