function Main(input) {
  let result = ""
  for (let i = 0; i < input.trim().length; i++) {
    let charCode = input.charCodeAt(i)
    result += (charCode < 97) ? String.fromCharCode(charCode + 32) : String.fromCharCode(charCode - 32)
  }
  console.log(result)
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"))