题解

#include<bits/stdc++.h>
using namespace std;
void Aa(char &x){
	if(x>='A'&&x<='Z')x+=32;
	else if(x>='a'&&x<='z')x-=32;
}
int main(){
	int a;
	string s;
	cin>>a;
	while(a--){
		cin>>s;
		int len=s.size();
		for(int i=0;i<s.size();i++){
			if(i==0&&s[i]>='a'&&s[i]<='z')Aa(s[i]);
			else if(i!=0&&s[i]>='A'&&s[i]<='Z')Aa(s[i]);
		}
		cout<<s<<endl;
	}
	return 0;
}