<span>HDU3627 set+map</span>

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <queue>
#include <vector>
#include <cstdio>
#include <set>
#include <map>
using namespace std;
set<int>s;
set<int>::iterator ss;
map<int,int>y;
map<int,set<int> >f;
map<int,set<int> >::iterator ff;
int main()
{
    //freopen("in.txt","r",stdin);
    int n,cas=1;
    while(~scanf("%d",&n)&&n)
    {
        if(cas!=1) printf("\n");
        s.clear();
        y.clear();
        f.clear();
        char str[10];
        int a,b;
        printf("Case %d:\n",cas++);
        while(n--)
        {
            scanf("%s%d%d",str,&a,&b);
            if(str[0]=='a')
            {
                if(y.find(b)==y.end()) y[b]=1;
                else y[b]++;
                if(s.find(a)==s.end()) s.insert(a);
                ff=f.find(a);
                if(ff==f.end()) f[a].insert(b);
                else
                {
                    ss=ff->second.find(b);
                    if(ss!=ff->second.end()) continue;
                    ff->second.insert(b);
                }
            }
            else if(str[0]=='f')
            {
                if(y.upper_bound(b)==y.end())
                {
                    printf("-1\n");
                    continue;
                }
                int p=a;
                while(1)
                {
                    if(s.empty())
                    {
                        printf("-1\n");
                        break;
                    }
                    ss=s.upper_bound(p);
                    if(ss==s.end())
                    {
                        printf("-1\n");
                        break;
                    }
                    else
                    {
                        int temp=*ss;
                        p=temp;
                        if(f[temp].empty()) continue;
                        ss=f[temp].upper_bound(b);
                        if(ss==f[temp].end()) continue;
                        else
                        {
                            printf("%d %d\n",temp,*ss);
                            break;
                        }
                    }
                }
            }
            else if(str[0]=='r')
            {
                f[a].erase(b);
                if(f[a].empty()) s.erase(a);
                if(!--y[b]) y.erase(b);
            }
        }
    }
    return 0;
}