#include <iostream>
#include <vector>
#include <string>
using namespace std;
class Solution
{
public:
    int findLUSlength(string a, string b)
    {
        if (a.length() > b.length())
            return a.length();
        else if (a.length() < b.length())
            return b.length();
        else if (a == b)
            return -1;
        return a.length();
    }
};
int main()
{
    Solution *s = new Solution();
    int ans = s->findLUSlength("aba", "abv");
    cout << ans << endl;
    return 0;
}