# Setup vars - a zero map and position map.
my ($pos,%bg_pos)    = (0,map { ($_,$pos++); }('aa'..'zz'));
my @bg_map           = (0) x 676;

# Input var
my @bg_input         = qw[ ab ba ca pe ne yt zz zy gh fg ui jk lk mn ad ]; 

# Do the actual map of matching bigrams
map { $bg_map[$bg_pos{$_}] = 1; } @bg_input;

# Output
print qq[
=====================================================
Row=1st Letter,Col=2nd Letter
=====================================================
  ],
  join(' ',('a'..'z')),"\n\n",
  map {( 
        "$_ ",
        ( map { (shift @bg_map)." "; } ('a'..'z') ),
        "\n"
  )} ('a'..'z');