package main

import (
	"fmt"
	"strings"
)

func main() {
	var s string
	fmt.Scan(&s)
	for i := 0; i < len(s); i++ {
		if 'a' <= s[i] && s[i] <= 'z' {
			fmt.Print(strings.ToUpper(string(s[i])))
		} else {
			fmt.Print(strings.ToLower(string(s[i])))
		}
	}
	fmt.Println()
}