using System;
using System.Linq;

class Solution
{
    static void Main()
    {
        Console.ReadLine(); // N is not needed
        var steps = Console.ReadLine().ToCharArray().Select(c => c == 'U');
        
        var valleysCount = 0;
        bool inValley = false;
        var height = 0;
        foreach (var stepUp in steps)
        {
            if (stepUp)
            {
                if (inValley && (height == -1))
                {
                    inValley = false;
                    ++valleysCount;
                }
            }
            else
            {
                // step down
                if (height == 0)
                {
                    // entering valley
                    inValley = true;
                }
            }
            
            height += stepUp ? 1 : -1;
        }
        
        Console.WriteLine(valleysCount);
    }
}