#include <stdio.h>

int main(int argc, char *argv[])
{
	switch(argc)
	{
		case  1: puts("argc == 1");    break;
		case  2: puts("argc == 2");    break;
		case  3: puts("argc == 3");    break;
		default: puts("argc ∉ [1,3]"); break;
	}
}