# use strict;
# use warnings;

sub sumNumsInStr {
    my $s = shift;
    my $c = 0;
    foreach (0 .. (length($s) - 1)) {
        my $x = substr($s, $_, 1);
        $c += int($x) if ($x ge '0' && $x le '9');
    }
    return $c;
}

chomp(my $S = <>);
print(sumNumsInStr($S), "\n");