unsigned long combinations(unsigned int m, unsigned int n) ;
unsigned long factorial(unsigned int n) ;
unsigned long permutations(unsigned int m, unsigned int n) ;

int minmax(int x, int y, int z, int *lo, int *hi) ;

void printChars(char c, int n) ;
void printStars(int n) ;
void printRect(char c, int width, int heigth) ;