function processData(input) {
    //Enter your code here
    var data = input.split("\n");
    var n = parseInt(data[0]);
    var steps = data[1].split("");
    
    var currentLevel = 0;
    var downwardSteps = 0;
    var valleys = 0; 
    
    for(i = 0; i < n; i++){
        
        if(steps[i] == "D" ){
            
             if(currentLevel < 1){ 
                 downwardSteps++;
             }
            
            currentLevel--;          
        }else{
            currentLevel++;
            
            if(downwardSteps == 1){
            //    downwardSteps = 0;
            }
        }
        
        if(currentLevel == 0){
            
            if(downwardSteps > 0){
                valleys++;
            }
            
            downwardSteps = 0;
        }
        
    }
    
    console.log(valleys);
    
} 

process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
   processData(_input);
});