#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

double findMedian(vector<int>& arr1, vector<int>& arr2) {
    int n1 = arr1.size();
    int n2 = arr2.size();

    // Merge the arrays into a single sorted array
    vector<int> merged(n1 + n2);
    merge(arr1.begin(), arr1.end(), arr2.begin(), arr2.end(), merged.begin());

    // Find the median
    int mid = (n1 + n2) / 2;
    if ((n1 + n2) % 2 == 0) {
        return (merged[mid - 1] + merged[mid]) / 2.0;
    } else {
        return merged[mid];
    }
}

int main() {
    int n1, n2;
    cin >> n1 >> n2;

    vector<int> arr1(n1);
    vector<int> arr2(n2);

    for (int i = 0; i < n1; i++) {
        cin >> arr1[i];
    }

    for (int i = 0; i < n2; i++) {
        cin >> arr2[i];
    }

    double median = findMedian(arr1, arr2);
    cout << fixed << setprecision(1) << median << endl;

    return 0;
}