1355  Super Chorus
Time Limit : 3 Second
Memory Limit : 128 MB
Submission: 534
Solved: 68
 Description
 Song is the leader of HUST chorus team. 3 second before a chorus competition he found his team which was already been arranged in a line was out of order, so he decided to eliminate some people to make sure that those m remaining students are bilateral symmetric in height and gender.(The ith person and the (mi+1)th person have the same height and gender.) The person in the middle was the tallest and the height strictly decreased from the middle to both sides.（If m is a even number ,then the person in the middle refers to the m/2th and (m/2+1)th student.） However, it was too difficult for him so he asked for your help.
 Input
 Multiple cases, end with EOF. Each case's first line is a positive integer n(0 < n <= 3000) which means the length of the chorus team. n lines followed and each line has two numbers, Hi and Gi. Hi is the height of the ist person.(measured by mm,100<=Hi<=1900) Gi is the gender of the the ist person. Gi=1 means male and Gi=0 means female.
 Output
 In each case you should output one integer indicating the max number of m.
 sample input

2 1730 1 1730 1 3 1650 0 1700 1 1650 0 3 1750 0 1670 1 1750 1
 sample output

2 3 1
 hint
 source
 Hust Monthly 10.04.05/xhSong