#include <stdio.h>

f(char*s){return(*s&=95)?f(s+1)>*s?*s:0:96;}

int main(void)
{
	int n;
	char tests[8][32] = {
		"a",
		"abcdefGHIjklmnopqrSTUVWXyz",
		"aa",
		"puz",
		"puzz",
		"puzZ",
		"puZ",
		"PuZ",
	};
	
	for (n = 0; n < 8; ++n)
		printf("%s => %s\n", tests[n], f(tests[n])?"true":"false");
	
	return 0;
}