#include<stdio.h>

int G,W,v[1002],v2[1002],i,j,k,ok,ok2;

int change(int &a,int &b)
{int aux;
aux=a;
a=b;
b=aux;
}


int main()
{
FILE*in=fopen("energii.in","r");
FILE*out=fopen("energii.out","w");
fscanf(in,"%d",&G);
fscanf(in,"%d",&W);
for(i=1;i<=G;i++)
 fscanf(in,"%d %d",&v[i],&v2[i]);
while(ok!=1)
{
 ok=1;
 for(i=2;i<=G;i++)
  if(v2[i]<v2[i-1]) {
                    change(v2[i],v2[i-1]);
                    change(v[i],v[i-1]);
                    ok=0;
                    }
}
ok2=1;
for(i=1;i<=G;i++)
 for(j=1;j<=G;j++)
 if(v[i]+v[j]>=W&&ok2!=0) {ok2=0;
                   fprintf(out,"%d\n ",v2[i]+v2[j]);
                  }

fcloseall();
return 0;
}