#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>

int main() {
    
    int numsteps;
    char *stepstr;
    int sea_lvl;
    int i,valley = 0;
    int vcnt = 0;

    /* Enter your code here. Read input from STDIN. Print output to STDOUT */    
    scanf("%d\n", &numsteps);
    stepstr = malloc(numsteps);
    for (i = 0; i < numsteps; i++)
        scanf("%c", &stepstr[i]);
   
    if (numsteps < 2 || numsteps > 1000000)
        return(-1);
    
    sea_lvl = 0;
    
    for(i=0; i<numsteps; i++) {
        if (stepstr[i] == 'U')
            sea_lvl++;
        else if (stepstr[i] == 'D')
            sea_lvl--;
        
        if (sea_lvl < 0)
            valley=1;
            
        if (valley == 1 && sea_lvl == 0) {
            vcnt++;
            valley = 0;
        }
    }
    free(stepstr);
        
    
    
printf("%d\n", vcnt);
    return 0;
}