#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

int main(){
    int n , i, altitude = 0, valleys = 0;
    scanf("%d",&n);
    char *steps = malloc( n);
    if( fgets (steps, n, std)!=NULL ) 
	{
	    //process steps
	    for(i = 0; i < n; i++){
	       if( steps[i] == 'U'){	
	       		if(altitude == -1){
	       			valleys++;
	       		}
	       		altitude++;
	       }
	       else{
	       	altitude--;
	       }
	    }
	}
 	printf("%d",valleys)
    return 0;
}