#include <bits/stdc++.h>
using namespace std;
int main() {
  int cnt, n;
  char f[3], st;
  while (1) {
    cin >> n;
    if (n == 0) return 0;
    cnt = 0;
    st = '-';
    for (int i = 0; i < n; i++) {
      cin >> f;
      if (st == '-')
        st = f[0];
      else if (st != f[0])
        cnt++;
    }
    cout << cnt << endl;
  }
  return 0;
}
