#include<stdio.h>

void qsort(int a[],int l,int r)
{
    
    int i=l,j=r,flag=a[(l+r)/2],t;
    do
    {
        while(a[i]>flag) i++;
        while(a[j]<flag) j--;
        if(i<=j)
        {
            t=a[i];a[i]=a[j];a[j]=t;
            i++;j--;
        }
    }while(i<=j);
    if(j>l) qsort(a,l,j);
    if(i<r) qsort(a,i,r);

}

int main()
{
    struct xs
    {
        int xh;
        int score;
    };
    struct xs a[10000];

    int n,m;
    scanf("%d %d",&n,&m);
    int pm=m*1.5;
    for(int i=0;i<n;i++)
    {
        scanf("%d %d",&a[i].xh,&a[i].score);
    }

    qsort(a[].score,0,n-1);//这里报错了

    for(int i=0;i<pm;i++)
    {
        printf("%d %d\n",a[i].xh,a[i].score);
    }
    return 0;
}