# use strict;
# use warnings;

chomp(my $N = <>);
my $c = 0;
if ($N > 1) {
    my $x = $N;
    until ($x < 2) {
        $x = $x >> 1;
        $c++;
    }
    $c++ if $N - (2 ** $c) != 0;
}
print($c, "\n");