#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
char a[10001];
int main()
{
    gets(a);
    int l=strlen(a);
    for(int i=0;i<l;i++)
    {
        if(a[i]>=‘A‘&&a[i]<=‘Z‘)
        a[i]=a[i]+32;
        else if(a[i]>=‘a‘&&a[i]<=‘z‘)
        a[i]=a[i]-32;
        //else cout<<a[i];
    }
    printf("%s\n",a);
    
    return 0;
}