#!/usr/bin/perl -w

# first_residue < foo.a2m
#
#	reads an a2m file and returns the first aligned (uppercase)
#	character in a sequence

while(<STDIN>)
{   next if /^>/;
    if (/([A-Z])/)
    {   print $1;
    	exit(0);
    }
}

die "ERROR: first_residue couldn't find any aligned letters in a2m file\n";