#include
     
      int main(){    int x1,y1;    int x,y;    int xm,ym,xa,ya;    while(scanf("%d %d",&x1,&y1)!=EOF&&(x1!=0||y1!=0))    {        xm=x1;//最小的x        xa=x1;//最大的y        ym=y1;        ya=y1;        while(scanf("%d %d",&x,&y)!=EOF&&(x!=0||y!=0))        {            if(x
      
       xa)xa=x;            if(y
       
        ya)ya=y;        }        printf("%d %d %d %d\n",xm,ym,xa,ya);    }}
       
      
     

        x和y都为0时，为结束符！