string.cpp

#include <iostream>
#include <string>
using namespace std;

int main() {
    string s1;
    string s2;
    cin >> s1 >> s2;
    
    cout << s1.length() << ' ' << s2.length() << endl;
    
    cout << s1 + s2 << endl;
    
    swap( s1[0], s2[0] );
    cout << s1 << ' ' <<  s2 << endl;
    
    return 0;
}