#include <stdio.h>
#include <iostream>
#include <math.h>
#include <iomanip>
using namespace std;
#define LL Long Long
const int N=1e5+10;
const int INF=0x3f3f3f3f;
int main()
{

    char a;
    cin>>a;
    if(a>=65&&a<=90){
            a+=32;
        }else if(a>=97&&a<=122){
            a-=32;
        }
    cout<<a;
    

}

#include <iostream>
using namespace std;
int main()
{
	char a;
	cin >> a;
	if(a >= 65 && a <= 90)
	{
		cout << (char)(a+=32);
	}
	else if(a >= 97 && a <= 122)
	{
		cout << (char)(a-32);
	}
	else
	{
		cout << a;
	}
	return 0;
}

#include using namespace std; int main () { char c; cin>>c; if('A'<=c&&c<='Z') { cout<<(char)(c+32); }else if(97<=c&&c<=122) { cout<<(char)(c-32); }else{ cout<<c; }
}

#include using namespace std; int main () { char c; cin>>c; if('A'<=c&&c<='Z') { cout<<(char)(c+32); }else if(97<=c&&c<=122) { cout<<(char)(c-32); }else{ cout<<c; }
}

#include using namespace std; int main () { char c; cin>>c; if('A'<=c&&c<='Z') { cout<<(char)(c+32); }else if(97<=c&&c<=122) { cout<<(char)(c-32); }else{ cout<<c; }
}

#include <iostream>
using namespace std;
int main()
{
	char a;
	cin>>a;
	if (a>=65&&a<90)
	{
		cout<<(a+=32);
	}
	else if(a>97&&a>122)
	{
		cout<<a-32;
	}
	return 0;
}

#include using namespace std; int main() { char x; cin>>x; if(65<=x and x<=90) { x = x + 32; cout<<x; }else if(97<=x and x<=122) { x=x-32; cout<<x; }else { cout<<x; } return 0; }

#include <iostream>
#include <stdio.h>
#include <iomanip>
#include <math.h>
using namespace std;
const int N = 1e6 + 10;
const int INF = 0x3f3f3f3f;
int main()
{
	char a;
	cin >> a;
	if( a <= 90 && a >= 65 )
	{
		a = a + 32;
		cout << a;
	}
	else if( a >= 61 && a <= 122 )
	{
		a = a - 32;
		cout << a;
	}
	else
	{
		cout << a;
	}
	return 0;
}

#include using namespace std; int main(){ char a; cin >>a; if(a>=65 && a<=90) a+=32; if(a>=97 && a<=122) a-=32; cout <<a; }

#include <stdio.h>
#include <iostream>
#include <math.h>
#include <iomanip>
using namespace std;
#define LL Long Long
const int N=1e5+10;
const int INF=0x3f3f3f3f;
int main()
{

    char a;
    cin>>a;
    if(a>=65&&a<=90){
            a+=32;
        }else if(a>=97&&a<=122){
            a-=32;
        }
    cout<<a;
    

}

#include<iostream>
#include<iomanip>
#include<stdio.h>
#include<math.h>
#include<string>
#include<cstring>
using namespace std;
int main(){
	char a;
	cin>>a;
	if('a'<=a&&a<='z')a=toupper(a);
	else if('A'<=a&&a<='Z')a=tolower(a);
	cout<<a;
	return 0;
}

#include <iostream>
using namespace std;
char a[5];
int main(){
   cin>>a[0];
    if(a[0]>=65&&a[0]<=90)
        a[0]+=32;
    else if(a[0]>=97&&a[0]<=122)
       a[0]-=32;
   cout<<a[0]<<endl;
    return 0;
}

#include <stdio.h>
#include <iostream>
using namespace std;
int main(){
    char a;
    cin>>a;
    if(a>=65&&a<=90){
            a+=32;
        }else if(a>=97&&a<=122){
            a-=32;
        }
    cout<<a;
    
}

//Write by: FSC711300
#include <bits/stdc++.h>
using namespace std;
int main(){
    char a;
    cin>>a;
    if(a>=65&&a<=90){
            a+=32;
        }else if(a>=97&&a<=122){
            a-=32;
        }
    cout<<a;
    
}

#include <iostream>
using namespace std;
int main()
{
	char a;
	cin>>a;
	if (a>=65&&a<90)
	{
		cout<<(a+=32);
	}
	else if(a>97&&a>122)
	{
		cout<<a-32;
	}
	return 0;
}

#include<bits/stdc++.h> using namespace std; int main() { char a; cin>>a; if(a>=65&&a<=90) a+=32; else if(a>=97&&a<=122) a-=32; cout<<a; return 0; }

#include #include using namespace std; int main() { int a; cin>>a; if(a%4==0&&a%100!=0) { cout<<"Y"; }else{ cout<<"N" ; } return 0; }

#include使用命名空间 std;int main（）{char a;辛>>;if（a>=65&&a<=90）{cout<<（char）（a+32）;}else{if（a>=97&&a<=122）{cout<<（char）（a-32） ;}else{cout<<a;}}返回 0;

}

n=input() if n.isupper()==True: print(n.lower()) elif n.islower()==True: print(n.upper()) else: print(n)