using System;
using System.Collections.Generic;
using System.IO;
class Solution
{
	static void Main(String[] args)
	{
		/* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution */
		int numberofSteps = Convert.ToInt32(Console.ReadLine());
		string stepLog = Console.ReadLine();

		int numberOfValleys = 0;
		int elevation = 0;
		bool atSeaLevel = true;

		for (int stepIndex = 0; stepIndex < numberofSteps; stepIndex++)
		{
			if (atSeaLevel && stepLog[stepIndex] == 'D')
			{
				numberOfValleys++;
			}

			if (stepLog[stepIndex] == 'D')
			{
				elevation--;
			}
			else
			{
				elevation++;
			}

			if (elevation == 0)
			{
				atSeaLevel = true;
			}
			else
			{
				atSeaLevel = false;
			}
		}

		Console.WriteLine(numberOfValleys);
	}
}