#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main(){
    int m, n;
    
    if (m < 0 || n < 0) {
        cout << "Invalid input";
        return 0;
    }
    
    vector<int> arr1(m), arr2(n);
    
    for (int i = 0; i < m; i++)
        cin >> arr1[i];
        
    for (int i = 0; i < n; i++)
        cin >> arr2[i];
        
    vector<int>merged;
    merged.insert(merged.end(),
arr1.begin(), arr1.end());
    merged.insert(merged.end(),
arr2.begin(), arr2.end());

    sort(merged.begin(), merged.end());
    
    int size = merged.size();
    
    if (size % 2 == 0)
        cout << (merged[size/2 - 1] +
merged[size/2]) / 2.0;
    else
        cout << merged[size/2];
        
    return 0;
}