# 【Splay】bzoj3223 Tyvj 1729 文艺平衡树

#include<cstdio>
#include<iostream>
#include<cstring>
#include<algorithm>
#include<stack>
using namespace std;
#define maxn 100010
#define INF 2147483647
int fa[maxn],val[maxn],c[maxn][2],root,tot,siz[maxn],cnt[maxn],val2[maxn];
bool delta[maxn];
void Maintain(int x)
{
siz[x]=siz[c[x][0]]+siz[c[x][1]]+cnt[x];
}
void Mark(int x){
if(x){
delta[x]^=1;
}
}
void pushdown(int x){
if(delta[x]){
Mark(c[x][0]);
Mark(c[x][1]);
swap(c[x][0],c[x][1]);
delta[x]=0;
}
}
void NewNode(int &x,int Fa,int key,int key2)
{
x=++tot;
fa[x]=Fa;
c[x][0]=c[x][1]=0;
val[x]=key;
val2[x]=key2;
siz[x]=cnt[x]=1;
}
void Rotate(int x,bool flag)
{
int y=fa[x];
c[y][!flag]=c[x][flag];
fa[c[x][flag]]=y;
if(fa[y]){
c[fa[y]][c[fa[y]][1]==y]=x;
}
fa[x]=fa[y];
c[x][flag]=y;
fa[y]=x;
Maintain(y);
Maintain(x);
}
stack<int>st;
void Splay(int x,int goal)
{
pushdown(x);
if(!x || x==goal){
return;
}
int U=x;
while(U!=root){
st.push(U);
U=fa[U];
}
st.push(U);
while(!st.empty()){
pushdown(st.top());
st.pop();
}
int y;
while((y=fa[x])!=goal){
if(fa[y]==goal){
Rotate(x,c[y][0]==x);
}
else{
if((c[y][0]==x)==(c[fa[y]][0]==y)){
Rotate(y,c[fa[y]][0]==y);
}
else{
Rotate(x,c[y][0]==x);
y=fa[x];
}
Rotate(x,c[y][0]==x);
}
}
Maintain(x);
if(!goal){
root=x;
}
}
int Find(int key,int x=root)
{
while(c[x][val[x]<key]){
if(val[x]==key){
return x;
}
x=c[x][val[x]<key];
}
return x;
}
void Insert(int key,int key2)
{
if(!root){
NewNode(root,0,key,key2);
return;
}
int x=Find(key);
if(val[x]==key){
++cnt[x];
Splay(x,0);
return;
}
NewNode(c[x][val[x]<key],x,key,key2);
Splay(c[x][val[x]<key],0);
}
int Kth(int K,int x=root)
{
while(1){
pushdown(x);
int Siz0=siz[c[x][0]];
if(K<=Siz0){
x=c[x][0];
}
else if(K<=Siz0+cnt[x]){
break;
}
else{
K-=(Siz0+cnt[x]);
x=c[x][1];
}
}
return x;
}
void print(int x)
{
if(!x){
return;
}
pushdown(x);
print(c[x][0]);
printf("%d ",val2[x]);
print(c[x][1]);
Maintain(x);
}
int n,m;
int main(){
scanf("%d%d",&n,&m);
Insert(0,0);
for(int i=1;i<=n;++i){
Insert(i,i);
}
Insert(n+1,n+1);
int x,y;
for(int i=1;i<=m;i++){
scanf("%d%d",&x,&y);
Splay(Kth(x),0);
Splay(Kth(y+2),root);
Mark(c[c[root][1]][0]);
}
Splay(Kth(1),0);
Splay(Kth(n+2),root);
print(c[c[root][1]][0]);
return 0;
}