#include<fstream.h>
int main ()
{int a [30][30],i,j,n,m,p=1,g=0;
cin>>n;
cin>>m;
for (i=1;i<=n;i++)
 for (j=1;j<=m;j++)
    cin>>a[i][j];
for (i=1;i<=n;i++)
 for (j=1;j<=m;j++)
  if (a[i][j]>0 && i%2==0 && j%2!=0)
    { p=p*a[i][j]%10;
      g=1;
    }
if(g) cout<<p;
else cout<<"nu exista";
return 0;
}