#include<bits/stdc++.h>
using namespace std;
#define int long long
inline int read(){
    int s=0,w=1;
    char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    return s*w;
}
inline void write(int x){
    if(x==0){putchar('0');return;}
    int len=0,k1=x,c[10005];
    if(k1<0)k1=-k1,putchar('-');
    while(k1)c[len++]=k1%10+'0',k1/=10;
    while(len--)putchar(c[len]);
}
const int N=5e6+5,mod=998244353;
int inv[N],fac[N];
struct solve1{
    void init(int n){
        inv[0]=inv[1]=1;fac[1]=1;
        for(int i=2;i<=n;i++){
            inv[i]=(mod-mod/i)*inv[mod%i]%mod;
            inv[i]=inv[i]*inv[i-1]%mod;fac[i]=fac[i-1]*i%mod;
        }
    }
    int c(int n,int m){
        if(n<m)return 0;
        return fac[n]*inv[m]%mod*inv[n-m]%mod;
    }
}s1;
signed main(){
    int t=read(),nn=read(),ans=0;
    s1.init(nn);
    while(t--){
        int n=read(),m=read();
        ans^=s1.c(n,m);
    }
    cout<<ans;
    return 0;
}