#include<iostream>
#include<cstdio>
#define ll long long
using namespace std;
ll a[100005],b[100005];
ll n,p;
ll ans;
ll s[8005],ins[8005];
ll qpow(ll a,ll k){
    ll res=1;
    while(k){
        if(k&1)
            res=res*a%p;
        k>>=1;
        a=a*a%p;
    }
    return res;
}
ll c(ll n,ll m){
    if(n<m) return 0;
    return s[n]*ins[m]%p*ins[n-m]%p;
}
int main(){
    freopen("BBQ.in","r",stdin);
    freopen("BBQ.out","w",stdout);
    scanf("%lld%lld",&n,&p);
    s[0]=ins[0]=1;
    for(ll i=1;i<=8000;i++){
        s[i]=(s[i-1]*i)%p;
        ins[i]=ins[i-1]*qpow(i,p-2)%p;
    }
    for(int i=1;i<=n;i++)
        scanf("%lld%lld",&a[i],&b[i]);
    for(int i=1;i<=n;i++){
        for(int j=i+1;j<=n;j++){
            ans=(ans+c(a[i]+a[j]+b[i]+b[j],a[i]+a[j]))%p;
        }
    }
    printf("%lld",ans);
    return 0;
}