#include <iostream>
#include <algorithm>

using namespace std;


typedef struct{
    int start;
    int end;
}segment;

bool isShorter(const segment &s1,const segment &s2);
segment commonSegment(const segment &seg_a,const segment &seg_b);
int findLongestSegment(const vector<segment> &segments,int size,segment &maxSegment);

int main()
{
    int n;
    int start,end;
    while(cin>>n){
        vector<segment> segments(n);
        for(int i=0;i<n;i++){
            if(cin>>start && cin>>end){
                segments[i].start=start;
                segments[i].end=end;
            }
        }

        // sort by segment.end
        sort(segments.begin(),segments.end(),isShorter);

        segment maxSeg;
        int maxLen;

        maxLen=findLongestSegment(segments,n,maxSeg);

        cout<<"Longest Length:"<<maxLen<<endl;
        cout<<"start:"<<maxSeg.start<<endl;
        cout<<"end:"<<maxSeg.end<<endl;
    }

    return 0;
}

bool isShorter(const segment &s1,const segment &s2){
    return s1.end<s2.end;
}


//assume seg_a.end<seg_b.end
segment commonSegment(const segment &seg_a,const segment &seg_b){
    segment commonSeg;
    if(seg_a.end<seg_b.start){
        commonSeg.start=0;
        commonSeg.end=0;
    }
    else{
        commonSeg.start=seg_b.start;
        commonSeg.end=seg_a.end;
    }
    return commonSeg;
}

int findLongestSegment(const vector<segment> &segments,int size,segment &maxSegment){
    if(size<=0)
        return 0;
        /*
    if(size==1){
        maxSegment.start=segments[0].start;
        maxSegment.end=segments[0].end;
        return maxSegment.end-maxSegment.start;
    }
        */
    if(size==2){
        maxSegment=commonSegment(segments[0],segments[1]);
        return maxSegment.end-maxSegment.start;
    }

    // size>2
    // dynamic programming
    int maxLen,tmpLen;
    segment tmpMaxSeg;
    maxLen=findLongestSegment(segments,size-1,tmpMaxSeg);
    maxSegment=tmpMaxSeg;

    // maxSegment=(maxSegment,commonSeg)
    segment commonSeg;
    for(int i=0;i<size-1;i++){
        commonSeg=commonSegment(segments[i],segments[size-1]);
        tmpLen=commonSeg.end-commonSeg.start;
        if(tmpLen>maxLen){
            maxLen=tmpLen;
            maxSegment=commonSeg;
        }
    }

    return maxSegment.end-maxSegment.start;
}