#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n;
  scanf("%d", &n);
  char str[150 * 4 + 1];
  scanf("%d", &n);
  fgets(str, sizeof(str) / sizeof(char), stdin);
  int left = 0, right = 0;
  int ans = 0;
  int current = 0;
  for (int i = 0; i < 3 * n; i = i + 3) {
    if (str[i] == 'l') {
      left = 1 - left;
    }
    if (str[i] == 'r') {
      right = 1 - right;
    }
    if (left == right && left != current) {
      ans++;
      current = 1 - current;
    }
  }
  printf("%d \n", ans);
  return 0;
}
