#include<bits/stdc++.h>
using namespace std;
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n,p;
    cin>>n>>p;
    vector<int> s(n),t(n);
    for(auto &x:s)cin>>x;
    for(auto &x:t)cin>>x;
    sort(s.begin(),s.end());
    sort(t.begin(),t.end());
    const int N = 50;
    vector<int> fac(N,1),ifac(N,1);
    for(int i=2;i<N;++i){
        fac[i] = (fac[i-1]*1ll*i)%p;
        ifac[i] = p-(((p/i)*1ll*ifac[p%i])%p);
    }
    for(int i=2;i<N;++i){
        ifac[i] = (ifac[i]*1ll*ifac[i-1])%p;
    }
    unordered_map<long long,int> ans;
    function<int(int,long long)> solve = [&](int i,long long hsh){
        if(!hsh)return 1;
        auto it = ans.find(hsh);
        if(it!=ans.end())return it->second;
        int cur = 0;
        for(int j=n-1;j>=0;--j){
            if(t[j]<s[i])break;
            if(!((hsh>>j)&1))continue;
            cur = (cur+(ifac[t[j]-s[i]]*1ll*solve(i-1,hsh^(1ll<<j))))%p;
        }
        return ans[hsh]=cur;
    };
    int T = 0;
    for(int i=0;i<n;++i)T+=(t[i]-s[i]);
    int fans = 1;
    for(int i=1;i<=T;++i)fans = (fans*1ll*i)%p;
    cout<<((fans*1ll*solve(n-1,(1ll<<n)-1))%p);
    return 0;
}