#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

int num_valleys(vector<char> input) {
    int current_level = 0;
    int num_valleys = 0;
    bool below_sea = false;
    for (int i = 0; i < input.size(); i++) {
        if (input[i] == 'U') {
            current_level++;
            if (below_sea == true && current_level >= 0) {
                below_sea = false;
                num_valleys++;
            }
        } else {
            current_level--;
            if (current_level < 0) {
                below_sea = true;
            }
        }
    }
    return num_valleys;
}


int main() {
    int n;
    cin >> n;
    vector<char> input;
    for (int i = 0; i < n; i++) {
        char in;
        cin >> in;
        input.push_back(in);
    }
    cout << num_valleys(input);
    return 0;
}