#include <bits/stdc++.h>
using namespace std;
#define int long long
#define N 500005
#define f first
#define s second
const int inf = 1e18;
int tc = 1, n, m;
pair<int,int> a[N];
int32_t main() {
ios::sync_with_stdio(0);cin.tie(0);
cin >> n >> m;
for(int i = 1; i <= n; i++) {
cin >> a[i].f;
}
for(int i = 1; i <= n; i++) {
cin >> a[i].s;
}
sort(a + 1, a + n + 1);
int l = 1, r = 1e18, jog = -1, j = 0;
while(l <= r) {
int mid = (l + r) / 2;
int c1 = 0, c = 0;
for(int i = n; i >= 1; i--) {
}
if(c1) r = mid - 1;
else {
l = mid + 1;
jog = mid;
}
}
cout << jog << endl;
return 0;
}
