#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[]){
    char str[200];
    scanf("%s",str);
    
    int i = 0;
    for(int i = 0; i < strlen(str); i++)
    {
        if('a' <= str[i] && str[i] <= 'z')str[i] -= ('a' - 'A');
        else if('A' <= str[i] && str[i] <= 'Z')str[i] += ('a' - 'A');
    }
    
    printf("%s", str);
    
    return 0;
}