function processData(input) {
    //Enter your code here
    var chunks = input.split('\n');
    var stepCount = parseInt(chunks[0]);
    var steps = chunks[1];
    var valleys = 0;
    var height = 0;
    for(var i = 0; i < stepCount; i++){
        
        if(steps.charAt(i) == 'D'){
            if(height == 0){
                valleys++;
            }
            height++;
        } else {
            height--;
        }
        
        
    }
    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);
});