#! /client/bin/perl

@text = <>;

for ($i=0; $i<=$#text; $i++) {
  if ($text[$i] =~ /[@]/) {
    $x[$k] = length $`;
    $y[$k] = $i;
    $k++;
    if ($text[$i] =~ /^([^@]*[@][^@]*)[@][^@]*$/) {
      $x[$k] = length $1;
      $y[$k] = $i;
      $k++;
    } elsif ($text[$i] =~ /[@].*[@].*[@]/) {
      $k += 2;
    };
  };
};

die "not exactly two @ in file" if $k != 2;

if (abs ($x[1]-$x[0]) > ($y[1]-$y[0])) { # flat line
  $m = ($y[1] - $y[0]) / ($x[1] - $x[0]);
  $b = $y[0] - $m * $x[0] + 0.5;
  if ($x[1] >= $x[0]) {
    for ($x=$x[0]; $x<=$x[1]; $x++) {
      $y = int ($m * $x + $b);
      &overwrite;
    };
  } else {
    for ($x=$x[0]; $x>=$x[1]; $x--) {
      $y = int ($m * $x + $b);
      &overwrite;
    };
  };
} else { # steep line
  $m = ($x[1] - $x[0]) / ($y[1] - $y[0]);
  $b = $x[0] - $m * $y[0] + 0.5;
  for ($y=$y[0]; $y<=$y[1]; $y++) {
    $x = int ($m * $y + $b);
    &overwrite;
  };
};

for ($i=0; $i<=$#text; $i++) {
  print $text[$i];
};

sub overwrite {
  my ($miss);
  $miss = $x - length ($text[$y]) + 2;
  if ($miss > 0) {
    chop $text[$y];
    $text[$y] .= sprintf ("%$miss"."s\n", "");
  };
  substr ($text[$y], $x, 1) = '@';
}