function processData(input) {
    const [, [steps]] = input.split('\n').map( (line) => line.split(' ') );
    
    let elevation = 0;
    let valleys = 0;
    
    for (const step of steps) {
        let prevElevation = elevation;
        elevation += (step == 'U' ? 1 : -1);
        if (elevation == 0 && prevElevation < 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);
});