package main

import "fmt"

func main() {
	var s string
	fmt.Scan(&s)
	for i := range s {
		if int(s[i]) >= int('a') {
			fmt.Print(string(int(s[i]) - int('a') + int('A')))
		} else {
			fmt.Print(string(int(s[i]) - int('A') + int('a')))
		}
	}
	fmt.Println()
}