next if( $c == 0 and $c++ );

##</code><code>##

File 1    File 2    File 3
  5         1         5
  6         2         6
  7         5         7
  8         6         8

##</code><code>##

5 |   | 5
6 |   | 6
7 |   | 7
8 |   | 8

##</code><code>##

5 | 5 | 5
6 | 6 | 6
7 |   | 7
8 |   | 8