var n: Int = Int(readLine()!)!
var inputs: String = readLine()!

var currentPos:Int = 0
var numValleys:Int = 0

var enteringValley:Bool = false
for direction in inputs.characters {
    var deltaPos: Int = (String(direction) == "U" ? +1 : -1)
    if currentPos == 0 && deltaPos == -1 {
        enteringValley = true
    } else if enteringValley == true && (currentPos == -1 && deltaPos == 1) {
        enteringValley = false
        numValleys += 1
    }
    currentPos += deltaPos
}

print(numValleys)