#include<iostream>
#include<algorithm>
#include<queue>
#include<vector>
using namespace std;
const int maxn=1e6+7;
struct cow{
	int l,r;
	int num;
	int stalk;
};
class cmp1{
	public:
		bool operator()(cow x,cow y)
		{
			return x.l>y.l;
		}
};
class cmp2{
	public:
		bool operator()(cow x,cow y)
		{
			return x.r>y.r;
		}
};
int main()
{
	int n;scanf("%d",&n);cow tmp;
	priority_queue<cow,vector<cow>,cmp2> q2;
	priority_queue<cow,vector<cow>,cmp1> q1;
	vector<int> cctime; 
	vector<cow> mycow(n+1);vector<int> number(n+1);
	for(int i=1;i<=n;i++)scanf("%d%d",&mycow[i].l,&mycow[i].r),cctime.push_back(mycow[i].l),cctime.push_back(mycow[i].r+1),mycow[i].num=i,q1.push(mycow[i]);
	sort(cctime.begin(),cctime.end());
	cctime.erase(unique(cctime.begin(),cctime.end()),cctime.end());
	int cnt=0;
	queue<int> stall;
	int maxv=0;
	for(int j=0;j<cctime.size();j++)
	{
		int i=cctime[j];
		while(!q2.empty()&&i>q2.top().r)
		{
			stall.push(q2.top().stalk);
		//	cout<<i<<"*****stall**"<<q2.top().stalk<<"******"<<q2.top().l<<"***outout**"<<q2.top().r<<endl;
			number[q2.top().num]=q2.top().stalk;
			q2.pop();
		}
		while(!q1.empty()&&i>=q1.top().l)
		{
			if(stall.empty())++cnt,stall.push(cnt);
			cow tmp=q1.top();tmp.stalk=stall.front();
		//	cout<<i<<"************intint******stall****"<<tmp.stalk<<"****************"<<tmp.l<<"   "<<tmp.r<<endl;
			q2.push(tmp);q1.pop();stall.pop();
		}
	}
	cout<<cnt<<endl;
	for(int i=1;i<=n;i++)cout<<number[i]<<endl;
 }