#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ff first
#define ss second
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define ertunt return
const int MOD = 998244353;
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
int main() {
ll n, m;
cin >> n >> m;
ll a[n], b[n];
for(ll i = 0; i < n; i++) cin >> a[i];
for(ll i = 0; i < n; i++) cin >> b[i];
ll ans = 0;
for(ll i = 0; i < n; i++){
ans = max(ans,max(a[i],b[i]));
}
cout << ans;
}
