Set

#include <fstream>
#include <set>
using namespace std;
ifstream f("set.in");
ofstream g("set.out");
set <int> S;
int n,op,x,y,t;

int main()
{
    f>>n;
    for(int i=1;i<=n;++i)
    {
        f>>op;
        if(op==1)
        {
            f>>x;
            S.insert(x);
        }
        if(op==2)
        {
            f>>x;
            t=*S.lower_bound(x);
            if(S.empty()) /// Daca setul S e vid
                g<<-1<<'\n';
            else
                if(x<=*S.rbegin()) /// Daca x se afla in set
                    g<<t<<'\n';
                else
                    g<<-1<<'\n';
        }
        if(op==3)
        {
            f>>x>>y;
            if(y>=*S.begin())
                while(S.lower_bound(x)!=S.end()&&*S.upper_bound(x)<=y)
                    S.erase(*S.lower_bound(x));
        }
    }
    return 0;
}