随机情况下是期望是O(1)的

// Problem: “经典”问题
// Contest: NowCoder
// URL: https://ac.nowcoder.com/acm/contest/11201/B
// Memory Limit: 524288 MB
// Time Limit: 4000 ms
// 2022-06-17 19:10:21
//
// Powered by CP Editor (https://cpeditor.org)

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

#define rep(i,l,r) for(int i=(l);i<=(r);i++)
#define per(i,l,r) for(int i=(l);i>=(r);i--)
#define ll long long
#define mset(s,t) memset(s,t,sizeof(t))
#define mcpy(s,t) memcpy(s,t,sizeof(t))
#define fi first
#define se second
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define SZ(x) ((int)(x).size())
#define mp make_pair

typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> Vll;
typedef vector<pair<int, int> > vpii;
typedef vector<pair<ll, ll> > vpll;

const ll mod = 1e9 + 7;
//const ll mod = 998244353;
const double pi = acos(-1.0);
inline ll ksc(ll x,ll y,ll mod)
{
ll ans = 0;
while (y) {
if (y & 1)
ans = (ans + x) %mod;
y >>= 1;
x = (x + x) %mod;
}
return ans;
}
inline ll qmi (ll a, ll b) {
ll ans = 1;
while (b) {
if (b & 1) ans = ans * a;
a = a * a;
b >>= 1;
}
return ans;
}
inline int read () {
int x = 0, f = 0;
char ch = getchar();
while (!isdigit(ch)) f |= (ch=='-'),ch= getchar();
while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();
return f?-x:x;
}
template<typename T> void print(T x) {
if (x < 0) putchar('-'), x = -x;
if (x >= 10) print(x/10);
putchar(x % 10 + '0');
}
inline ll sub (ll a, ll b) {
return ((a - b ) %mod + mod) %mod;
}
inline ll add (ll a, ll b) {
return (a + b) %mod;
}
// inline ll inv (ll a) {
// return qmi(a, mod - 2);
// }
int a[10000001],c[10000002][2],n,m;
unsigned int rd;
inline int rnd(int mod,int seed)
{
rd^=(1<<13);
rd^=(rd>>7);
rd^=(rd<<20);
rd^=(rd>>3);
rd^=(rd<<10);
rd^=(rd<<5);
rd^=(1<<2);
return rd%mod+seed;
}
// 生成序列 a
void make_sequence()
{
for(int i=1;i<=n;i++)
{
a[i]=i-1;
}
for(int i=1;i<=n;i++)
{
swap(a[i],a[rnd(n,1)]);
}
}
// 生成一个询问,表示查询区间 [l,r] 的 mex
pair<int,int> make_query()
{
int l=rnd(n,1);
int r=rnd(n+1-l,l);
return make_pair(l,r);
}

void solve() {
cin >> n >> m;
ll ans = 0;
make_sequence();
vector<int> p(n);
for (int i = 0; i < n; i ++)
p[a[i]] = i;
for (int i = 1; i <= m ;i ++) {
auto [l, r] = make_query();
int x = 0;
l --, r --;
while(x < n && p[x] >= l && p[x] <= r)
x ++;
ans ^= x;
}
cout << ans << endl;

}
int main () {
// ios::sync_with_stdio(0),cin.tie(0), cout.tie(0);
int t;
t =1;
//cin >> t;
while (t --) solve();
return 0;
}