#!/usr/bin/perl

$NMax = 0;
while ( <> ) {
    chop;
    if ( $_ =~ "<doc" ) {
	if ( defined $Hist[$n] ) {
	    $Hist[$n]++;
	}
	else {
	    $Hist[$n] = 1;
	}
	if ( $n > $NMax ) {
	    $NMax = $n;
	}
	$n=0;
    } 
    else {
        $n++;
    }
}

for ( $i=0; $i < $NMax+1; $i++ ) {
    if ( defined $Hist[$i] ) {
	printf "$i $Hist[$i]\n";
    }
    else {
	printf "$i 0\n";
    }
}
