int main(){
char ch;
ch = getchar();
while(ch != '\n'){
if(ch>='A' && ch <='Z'){
ch = ch - 'A' + 'a';
}
else if(ch<='z' && ch>= 'a'){
ch = ch -'a' + 'A';
}
putchar(ch);
ch = getchar();
}
}