#include<fstream>
using namespace std;
ifstream fin("date.in");
ofstream fout("date.out");

struct spectacol
{
    int s,d;
};

void citire(int &n, spectacol a[])
{
    fin>>n;
    for(int i=1;i<=n;i++)
        fin>>a[i].s>>a[i].d;
}

void ordonare(int n, spectacol a[])
{
    int i,j;
    spectacol aux;
    for(i=1;i<n;i++)
        for(j=i+1;j<=n;j++)
            if(a[i].d>a[j].d)
            {
                aux=a[i]; a[i]=a[j]; a[j]=aux;
            }
}

void afisare(int n, spectacol a[])
{
    for(int i=1;i<=n;i++)
        fout<<a[i].s<<","<<a[i].d<<" ";
}

void greedy(int n, spectacol a[])
{
    spectacol s[100];
    int i,k;
    k=1;
    s[1]=a[1];
    for(i=2;i<=n;i++)
        if(s[k].d<a[i].s) s[++k]=a[i];
    afisare(k,s);
}

int main()
{
    int n;
    spectacol a[100];
    citire(n,a);
    ordonare(n,a);
    greedy(n,a);
    fin.close();
    fout.close();
}