#pragma GCC optimize("O3", "unroll-loops") // "Ofast"
#pragma GCC target("avx2", "bmi", "bmi2", "lzcnt", "popcnt")
#include <bits/stdc++.h>
//#define int long long
#define vt vector
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
#define f first
#define s second
#define dbg(x) cerr << #x << " = " << x << '\n'
#define bit(x, i) ((x) >> (i) & 1)
using namespace std;
using ll = long long;
using ld = long double;
using pii = pair<int, int>;
const int N = 1e6 + 5, mod = 1e9 + 7;
const ll inf = 1e18 + 7;
const ld eps = 1e-6;
int n, m, a[N], t[N];
vt<pii> v;
void solve () {
cin >> n >> m;
for (int i = 1; i <= m; i++) cin >> t[i];
for (int i = 1; i <= m; i++) cin >> a[i], v.pb({t[i], a[i]});
sort(all(v));
bool ok = 1;
for (int i = 0; i < m - 1; i++) {
if (v[i + 1].f - v[i].f < abs(v[i + 1].s - v[i].s)) ok = 0;
}
cout << (ok ? 1 : 2);
cout << '\n';
}
bool testcases = 0;
signed main() {
#ifdef ONLINE_JUDGE
freopen(".in", "r", stdin);
freopen(".out", "w", stdout);
#endif
cin.tie(0) -> sync_with_stdio(0);
int test = 1;
if (testcases) cin >> test;
for (int cs = 1; cs <= test; cs++) {
solve();
}
}
