def is_bad_version(s):
    return s >= v

def is_bad_version(s):
    return s >= v
    
def first_bad_version(n):

    # Assigning first pointer with the first version that is 1
    first = 1
    # Assigning last pointer with n that is the number of versions
    last = n
    calls = 0
    print("\n\tVersions: ", end="")
    for x in range(first, last):
        print(x, end=", ")
    print(last, "\n")
    # Binary search to find the target version
    while first < 2:  # Last should be equal to n.But here last = 2. Because we are calculating mid only one time here just to show how it works
        mid = first + (last - first) // 2;
        first += 1
        print("\n\tmid: ", mid)
        # is_bad_version() is the API function that returns true
        # or false depending upon whether the provided version ID
        # is bad or good
        if (is_bad_version(mid)):
            print(f"\tVersion {mid} is bad, so we search in the first half of the list.\n")
        else:
            print(f"\tVersion {mid} is good, so we search in the second half of the list.\n")

    return first, calls

# Driver code


def main():
    global v
    test_case_versions = [38, 13, 29, 40, 23]
    first_bad_versions = [28, 10, 10, 28, 19]

    for i in range(len(test_case_versions)):
        v = first_bad_versions[i]
        print(i + 1,  ".\tNumber of versions: ", test_case_versions[i], sep="")
        first_bad_version(test_case_versions[i])
        print("-"*100)


if __name__ == '__main__':
    main()