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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int number_of_steps{0};
    cin >> number_of_steps;
    
    int number_of_valleys{0};
    char step_condition{'F'};
    int sea_level{0};
    int sea_level_before{0};
    for (int step = 0; step < number_of_steps; step++){
        cin >> step_condition;
        sea_level_before = sea_level;
        
        if (step_condition == 'U'){
            sea_level++;
        }
        else if (step_condition == 'D'){
            sea_level--;
        }
        
        if (sea_level == 0 && sea_level_before == -1)
            number_of_valleys++;
    }
    cout << number_of_valleys;
    return 0;
}