function processData(input) {
    var s = input.split('\n')[1];
    var h = 0;
    var cnt = 0;
    for (var i in s) {
        if (s[i] == 'U') {
          h++;  
        }  
        else {
            h--;
            if (h == -1)
                cnt++;
        }
    }
    console.log(cnt);
} 

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

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