{
	split(substr($0,1,length($0)/2),arr,"")
	r = substr($0,1+length($0)/2)
	for (a in arr) {
		c = arr[a]
		if (index(r,c)>0) {
			comm = c
		}
	}
	S += index("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ", comm)
}
END {print S}