#include <bits/stdc++.h>
using namespace std;

typedef long long LL;
typedef double dbl;

#define all(x) (x).begin(), (x).end()
#ifdef _DEBUG
# define LOG(x...) fprintf(stderr, x)
#else
# define LOG(x...) 0
#endif

const int INF = 1000000000;
const int MOD = 1000000007;
const dbl EPS = 1e-9;

int main() {
#ifdef _DEBUG
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif
  cin.tie(0);
  cin.sync_with_stdio(0);

  int n;
  cin >> n;
  
  string s;
  cin >> s;
  
  int level = 0, valleys = 0;
  
  for (int i = 0; i < n; ++i) {
    if (s[i] == 'D' && level == 0) valleys++;
    if (s[i] == 'D') 
      level--;
    else
      level++;
  } 

  cout << valleys << endl;

  return 0;
}