let s = require('fs').readFileSync('/dev/stdin', 'utf8').split('\n')[0]
let a = 'a'.charCodeAt(0)
let z = 'z'.charCodeAt(0)
let o = ""
Array.prototype.forEach.call(s, (e) => {
  let c = e.charCodeAt(0)
  if (a <= c && c <= z) o += e.toUpperCase()
  else o += e.toLowerCase()
})
console.log(o)