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

#define rep(i,a,b) for(int i=(a),i##end=(b);i<=i##end;++i)
#define per(i,a,b) for(int i=(a),i##end=(b);i>=i##end;--i)
mt19937 Rnd(chrono::high_resolution_clock::now().time_since_epoch().count());
template<typename T>void chkmax(T&x,const T&y){if(x<y)x=y;}
template<typename T>void chkmin(T&x,const T&y){if(y<x)x=y;}

#define pb push_back
#define ALL(x) (x).begin(),(x).end()
#define mem(x) memset((x),0,sizeof(x))

typedef double db;
typedef long long ll;
typedef vector<int>vi;
typedef pair<int,int>pii;

typedef unsigned u32;
typedef unsigned uint;
typedef unsigned long long u64;

namespace orzjk{
  const int SZ=1e6;
  char buf[SZ],*p1=buf,*p2=buf;
  char nc(){
    return p1==p2&&(p2=(p1=buf)+fread(buf,1,SZ,stdin),p1==p2)?EOF:*p1++;
  }
  char fub[SZ],*p3=fub,*p4=fub+SZ;
  void pc(char c){
    p3==p4&&(fwrite(fub,1,SZ,stdout),p3=fub);
    *p3++=c;
  }
  void flush(){
    fwrite(fub,1,p3-fub,stdout),p3=fub;
  }
}
using orzjk::nc;
using orzjk::pc;

//#define nc getchar
//#define pc putchar

int read(){
  int x=0,f=1;char c=nc();
  while(c<48)c=='-'&&(f=-1),c=nc();
  while(c>47)x=x*10+(c^48),c=nc();
  return x*f;
}
template<class T>void write(T x){
  static char st[41];
  if(!x)return pc(48),void();
  char*p=st;
  if(x<0)x=-x,pc('-');
  for(;x;x/=10)*p++=x%10|48;
  do{
    pc(*--p);
  }while(p!=st);
}

//const int P=1e9+7;
const int P=998244353;
int qp(int a,int k){
  int res=1;for(;k;k>>=1,a=1ll*a*a%P)if(k&1)res=1ll*res*a%P;return res;
}

const int maxn=5e5+10;

#define mid ((l+r)/2)

int rt,tot;
struct node{
  int ls,rs;
  uint s0,s1;
}tr[maxn*60];
void add(int&k,int l,int r,int pos,uint v0,uint v1){
  if(!k){
    k=++tot;
  }
  tr[k].s0+=v0;
  tr[k].s1+=v1;
  if(l<r)pos<=mid?add(tr[k].ls,l,mid,pos,v0,v1):add(tr[k].rs,mid+1,r,pos,v0,v1);
}
node ask(int k,int l,int r,int pos){
  if(!k)return{0,0,0,0};
  if(r<=pos){
    return tr[k];
  }
  if(pos<=mid){
    return ask(tr[k].ls,l,mid,pos);
  }else{
    node o=ask(tr[k].rs,mid+1,r,pos);
    o.s0+=tr[tr[k].ls].s0;
    o.s1+=tr[tr[k].ls].s1;
    return o;
  }
}

#undef mid

void solve(){
  uint n,m;
  n=read(),m=read();
  uint las=0;
  for(uint i=1;i<=n;i++){
    uint l=(read()+las)%(1<<m);
    uint r=(read()+las)%(1<<m);
    if(l>r)swap(l,r);
    
    add(rt,0,(1<<m)-1,l,i,i*l);
    if(r<(1u<<m)-1)add(rt,0,(1<<m)-1,r+1,-i,-i*(r+1));
    
    node o=ask(rt,0,(1<<m)-1,r);
    las+=o.s0*(r+1)-o.s1;
    if(l>0){
      o=ask(rt,0,(1<<m)-1,l-1);
      las-=o.s0*l-o.s1;
    }
//    cout<<las<<endl;
  }
  cout<<las<<endl;
}

signed main(){
//  freopen(".in","r",stdin);
//  freopen(".out","w",stdout);
//  int T;cin>>T;while(T--)solve();
  solve();
  orzjk::flush();
  return 0;
}