#include <stdio.h>

int main(int argc, char *argv[ ])
{
	if(argc!=3)
	{
		printf("usage:a.out <directory> <preix>");
		exit(1);
	}

	printf("%s\n", tempnam(argv[1][0]!=' '?argv[1]:NULL, argv[2][0]!=' '?argv[1]:NULL));
	exit(0);
}