#include<iostream>
#include<algorithm>
using namespace std;
int n,z;
bool flag[40010];
long long a[20005],b[20005],c[40010],ans;
int Search(long long x){
    for(int k=1;ik<=z-1;k++){
        if(c[k]==x) return k;
    }
    return 0;
}
int main(){
    cin>>n;
    int z=0;
    for(int i=1;i<=n;i++){
        cin>>a[i]>>b[i];
        c[++z]=a[i];
        c[++z]=b[i];
    }
    cout<<z<<endl;
    sort(c+1,c+z+1);
    for(int i=1;i<=n;i++){
        int begin=Search(a[i]);
        int end=Search(b[i]);
        cout<<begin<<endl;
        cout<<end<<endl;
        for(int j=begin;j<=end;j++){
            flag[j]=true;
        }
    }
    for(int i=1;i<=z;i++){
        if(flag[i]){
            ans+=c[i+1]-c[i];
        }
    }
    cout<<ans<<endl;
    return 0;
}