#! usr/bin/perl
use warnings;
use strict;
my @a = <> ;
my @b = ();
foreach (@a) {
 push (@b, split(/ /));
             }
my $i = 0;
my $j = 1;
my $min = $b[0];
my $x = 0;
while ($x++ < 150) {
    $j = $j+3;
    $i = $i+3;
 
        if ($b[$j] = $b[$j+3]) {

          if ($min > $b[$i]) {
                                   
                    $min = $b[$i]
                             }
                         
                               }
                   }

 print "$min\n";