#include <bits/stdc++.h>   using namespace std;   int main() {     char str[2020];     long l;     cin >> l;     cin >> str;     int i, j, hs = 0, ts = 0;     for (i = 0; i < l; i++) {       if (str[i] ==  H )         hs++;       else         ts++;       str[l + i] = str[i];     }     int res = 1000000000;     int t;     for (i = 0; i < l; i++) {       t = 0;       for (j = 0; j < hs; j++) {         if (str[i + j] ==  T ) t++;       }       if (t < res) res = t;       t = 0;       for (j = 0; j < ts; j++) {         if (str[i + j] ==  H ) t++;       }       if (t < res) res = t;     }     cout << res;     return 0;   }   