function processData(input) {
    //Enter your code here
    var level = 0;
    var valleys = 0;
    var steps = [0];
    for (i=0;i<_input.length;i++) {
        if (input[i] == 'U') {
            level++;
        } else if (input[i] == 'D') {
            level--;
        }
        steps.push(level);
    }
    for (i=1;i<=_input.length;i++) {
        if (steps[i] == 0) {
            if (steps[i-1] < 0) {
                valleys++;
            }
        }
    }
    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);
});