function processData(input) {
  var args = input.split('\n');
  var n = Number(args[0]);
  var topo = args[1];
  var belowSeaLevel = false;
  var level = 0;
  var valleysHiked = 0;
  for (let i = 0; i < n; i += 1) {
    // Adjust current level of hike
    if (topo.charAt(i) === 'D') {
      level -= 1;
    } else {
      level += 1;
    }
    if (level < 0) {
      belowSeaLevel = true;
    }
    if (belowSeaLevel && level === 0) {
      valleysHiked += 1;
      belowSeaLevel = false;
    }
  }
  console.log(valleysHiked);
} 

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

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