include<stdio.h>

int main() {

char a,b;
scanf("%c",&a);
if(a>='a'&&a<='z')
{
    b=a-32;
    printf("%c",b);
}
else if(a>='A'&&a<='Z')
{
    b=a+32;
    printf("%c",b);
}
else
{
    printf("%d",a);
}
return 0;

}