package main

import (
	"fmt"
	"strings"
)

func main() {
	var s string
	fmt.Scan(&s)

	ans := ""
	for i := range s {
		if 'a' <= s[i] && s[i] <= 'z' {
			ans += strings.ToUpper(string(s[i]))
		} else {
			ans += strings.ToLower(string(s[i]))
		}
	}
	fmt.Println(ans)
}