//my solution

include

using namespace std;

int main() { string a,b; cin>>a; cin>>b;

cout<<a.size()<<" "<<b.size()<<"\n";

cout<<a+b<<"\n";

char ca1 = b[0];
char cb1 = a[0];

a[0] = ca1;
b[0] = cb1;

cout<<a<<" "<<b;

return 0;

}

MY LOGIC TO SOLVE THIS PROBLEM.

string a, b; cin >> a; cin >> b;

cout << a.length() << " " << b.length() << endl;  
cout << (a + b) << endl;

char first_char_a = a[0];
char first_char_b = b[0];
a[0] = first_char_b;
b[0] = first_char_a;

cout << a << " " << b << endl;

include

using namespace std;

int main(){ string a,b; cin >> a >> b; cout << a.size() << " " << b.size() << endl; cout << a+b << endl; swap(a[0], b[0]); cout << a << " " << b << endl; return 0; }

include

include

using namespace std;

int main() { string a,b; cin>>a>>b; cout<

}

include

include

using namespace std;

int main() { // Complete the program string a , b ; cin>>a>>b; cout<

return 0;

}