http://acm.hdu.edu.cn/showproblem.php?pid=1050
#include<iostream>
#include<algorithm>
using namespace std;
struct Node
{
    int st;//總是保存小的
    int et;//總是保存大的
};
bool comp(Node a,Node b)
{
    if(a.st == b.st)
        return a.et<b.et;
    else
        return a.st<b.st;
}
Node infor[201];
int main()
{
    int cas,n;
    cin>>cas;
    while(cas--)
    {
        cin>>n;
        int i,j,k,a,b;
        int hash[201];
        for(i=0;i<n;i++)
        {
            cin>>a>>b;
            infor[i].st=a<b?a:b;
            infor[i].et=a>b?a:b;
        }
        sort(infor,infor+n,comp);
        k=0;
        hash[k++]=infor[0].et;
        for(i=1;i<n;i++)
        {
            for(j=0;j<k;j++)
            {
                if(hash[j]<infor[i].st)
                {
                    if(hash[j]%2==1 )//奇數(shù)時(shí)要考慮清楚
                    {
                        /*
                         3 5 7
                         4 6 8
                         4->5 、6->7需要20分鐘
                        */
                        if( infor[i].st - hash[j] > 1)
                        {
                            hash[j] = infor[i].et;
                            break;
                        }
                    }
                    else
                    {
                        hash[j] = infor[i].et;
                        break;
                    }
                }
            }
            if(j==k)
                hash[k++] = infor[i].et;
        }
        cout<<k*10<<endl;
    }
    return 0;
}