#include<bits/stdc++.h>
using namespace std;

#define ll long long
#define foru(a,b,c) for(ll a=b;a<=c;a++)
#define endl '\n'

ll n,p,a[5005],b[5005],f[10005],inv[10005];

ll pw(ll x,ll y){
    ll res=1;
    x%=p;
    while(y){
        if(y&1)res=res*x%p;
        x=x*x%p;
        y>>=1;
    }
    return res;
}

ll c(ll x,ll y){
    if(y<0||y>x)return 0;
    return f[x]*inv[y]%p*inv[x-y]%p;
}

int main() {
	freopen("BBQ.in","r",stdin);
	freopen("BBQ.out","w",stdout);
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin>>n>>p;
	f[0]=1;
	foru(i,1,1e4){
	    f[i]=f[i-1]*i%p;
    }
    inv[10000]=pw(f[10000],p-2);
    for(ll i=1e4-1;i>=0;i--)inv[i]=inv[i+1]*(i+1)%p;
    foru(i,1,n)cin>>a[i]>>b[i];
    ll ans=0;
    foru(i,1,n){
        foru(j,i+1,n){
            ans=(ans+c(a[i]+a[j]+b[i]+b[j],a[i]+a[j]))%p;
        }
    }
    cout<<ans;
	return 0;
}