function Main(input) {
  let data = input.split("");

  for (i=0; i<data.length; i++) {
    if (Boolean(data[i].match(/[A-Z]/))) {
      data[i] = data[i].toLowerCase();
    } else {
      data[i] = data[i].toUpperCase();
    }
  }

  process.stdout.write(data.join(""));
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));