#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 300;
int main() {
  string s;
  int h;
  cin >> h;
  cin >> s;
  int ans = s.size();
  for (int i = 1; s[i]; i++) {
    if ((s[i] == 'U' && s[i - 1] == 'R') || (s[i] == 'R' && s[i - 1] == 'U')) {
      s[i] = 'p';
      --ans;
    }
  }
  cout << ans << '\n';
}
