def findminmax(n):    if len(n) <= 0:        return None, None    min1 = n[0]    max1 = n[0]    for i in n[1:]:        j = int(i)        if j <= min1:            min1 = j    for m in n[1:]:        n = int(m)        if n >=max1:            max1 = n    return min1,max1print(findminmax([3,2,1,5,10]))print(findminmax([]))print(findminmax([7]))