package main

import (
	"bytes"
	"fmt"
	"strings"
)

var (
	S string
)

func resolve() string {
	var buf bytes.Buffer
	for _, s := range S {
		if s >= 'a' && s <= 'z' {
			buf.WriteString(strings.ToUpper(string(s)))
		} else {
			buf.WriteString(strings.ToLower(string(s)))
		}
	}
	return buf.String()
}

func main() {
	fmt.Scanf("%s\n", &S)
	fmt.Println(resolve())
}