giúp mình vs mình học C++

#include<bits/stdc++.h>
#define ll long long
#define ios ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#pragma GCC optimize("O3","unroll-loops")
#pragma GCC optimize("Ofast")
using namespace std;
string kt(string a, string b)
{
    if(a.length()>b.length())
        return a;
    else
        return b;
}
int main() {
    ios
    string a,b;
    getline(cin,a);
    getline(cin,b);
    cout<<kt(a,b);
    return 0;
}
/*


*   *  *   *    *     *   *
**  *  *   *   * *    **  *
* * *  *   *  *   *   * * *
*  **  *****  *****  *  **
*   *  *   *  *   *   *   *
*   *  *   *  *   *   *   *
*   *  *   *  *   *   *   *

*/

#include <bits/stdc++.h>
#define str string
using namespace std;
int main()
{
    str m,n;
    getline(cin,m);
    getline(cin,n);
    if(m.size()>n.size())
    {
        cout<<m;
    }
    else cout<<n;
}