#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
#include <map>
#include <stack>
#include <bitset>
#include <string>
#include <cstring>
#include <iterator>
#include <random>
#define ll long long
#define ll1 long long
#define ull unsigned long long
#define dou long double
#define str string
#define vll vector<ll>
#define vi vector<int>
#define pll pair<ll, ll>
#define vpll vector<pll>
#define vbool vector<bool>
#define vstr vector<str>
#define vvll vector<vll>
#define pb push_back
#define pf push_front
#define endl "\n"
#define fr first
#define se second
// #define sortcmp(a) sort(a.begin(), a.end(), cmp)
#define sort(a) sort(a.begin(), a.end())
#define reverse(a) reverse(a.begin(), a.end())
#define speed ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define INF 1000000000000000000
#define ordered_set tree<ll, null_type, less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update>
using namespace std;
//using namespace __gnu_pbds;
mt19937 rng(time(0));
ll randll(ll l, ll r){
return uniform_int_distribution<ll>(l, r)(rng);
}
bool f(ll n, ll m, vpll& a){
for(int i = 1; i < m; i ++){
if(a[i].fr-a[i-1].fr < abs(a[i].se-a[i-1].se)) return 0;
}
return 1;
}
int main(){
speed;
ll n, m;
cin >> n >> m;
vpll a(m);
for(int i = 0; i < m; i ++){
cin >> a[i].se;
}
for(int i = 0; i < m; i ++){
cin >> a[i].fr;
}
sort(a);
if(f(n, m, a)) cout << 1 << endl;
else cout << 2 << endl;
}
