#include <iostream>
using namespace std;
int n,nrcp,nr,nrcnp,i,x,aux,cma,c,t,cp,k,y,nr0,nr2,nr4,nr6,nr8;
int main()
{cin>>n>>t;
nrcp=0;
nr=0;
nrcnp=0;
for(i=1;i<=n;i++)
{cin>>x;
aux=x;
cma=0;
while(aux>0)
{c=aux%10;
aux=aux/10;
if(c>cma)
cma=c;}
nr=nr*10+cma;
if(cma==2||cma==3||cma==5||cma==7)
nrcp++;
else
nrcnp++;
if(nrcp==t)
cp=cma;}
if(nrcp>nrcnp)
{x=0;
for(k=9;k>=0;k--)
{aux=nr;
while(aux>0)
{c=aux%10;
aux=aux/10;
if(c==k)
x=x*10+c;}}
cout<<x<<'\n';}
else
{y=0;
nr0=0;
nr2=0;
nr4=0;
nr6=0;
nr8=0;
aux=nr;
while(aux>0)
{c=aux%10;
aux=aux/10;
if(c==0)
nr0++;
else
if(c==2)
nr2++;
else
if(c==4)
nr4++;
else
if(c==6)
nr6++;
else
if(c==8)
nr8++;}
if(nr2>0)
{y=2;
nr2--;}
else
if(nr4>0)
{y=4;
nr4--;}
else
if(nr6>0)
{y=6;
nr6--;}
else
if(nr8>0)
{y=8;
nr8--;}
for(i=1;i<=nr0;i++)
y=y*10;
for(i=1;i<=nr2;i++)
y=y*10+2;
for(i=1;i<=nr4;i++)
y=y*10+4;
for(i=1;i<=nr6;i++)
y=y*10+6;
for(i=1;i<=nr8;i++)
y=y*10+8;
if(y==0&&nr0==0)
cout<<-1<<'\n';
else
cout<<y<<'\n';}
if(nrcp<t)
cout<<-1;
else
cout<<cp;
return 0;
}