print("The Optimal Way of Paying a Sum of US Dollars")
print("pythonize.ir \t Programmer: Mohammad Rajabpur")
print("To exit the program, enter a negative amount.")
print("--------------------------------------- \n")
while True:
    n = float(input("n = "))
    n = round(n, 2)
    if n < 0:
        print("The program is terminated. Goodbye!")
        break
    elif n == 0:
        print("$0 = ")
        print("No bills and coins!")
        print("--------------------------------------- \n")
    else:
        print("$", n, "= ")
        r = ""
        b100 = n // 100
        if b100 == 1:
            r += str(int(b100)) + " hundred-dollar bill \n"
        elif b100 > 1:
            r += str(int(b100)) + " hundred-dollar bills \n"
        n = n % 100
        b50 = n // 50
        if b50 == 1:
            r += str(int(b50)) + " fifty-dollar bill \n"
        elif b50 > 1:
            r += str(int(b50)) + " fifty-dollar bills \n"
        n = n % 50
        b20 = n // 20
        if b20 == 1:
            r += str(int(b20)) + " twenty-dollar bill \n"
        elif b20 > 1:
            r += str(int(b20)) + " twenty-dollar bills \n"
        n = n % 20
        b10 = n // 10
        if b10 == 1:
            r += str(int(b10)) + " ten-dollar bill \n"
        elif b10 > 1:
            r += str(int(b10)) + " ten-dollar bills \n"
        n = n % 10
        b5 = n // 5
        if b5 == 1:
            r += str(int(b5)) + " five-dollar bill \n"
        elif b5 > 1:
            r += str(int(b5)) + " five-dollar bills \n"
        n = n % 5
        b2 = n // 2
        if b2 == 1:
            r += str(int(b2)) + " two-dollar bill \n"
        elif b2 > 1:
            r += str(int(b2)) + " two-dollar bills \n"
        n = n % 2
        b1 = n // 1
        if b1 == 1:
            r += str(int(b1)) + " one-dollar bill \n"
        elif b1 > 1:
            r += str(int(b1)) + " one-dollar bills \n"
        n = n % 1 * 100
        q = n // 25
        if q == 1:
            r += str(int(q)) + " quarter \n"
        elif q > 1:
            r += str(int(q)) + " quarters \n"
        n = n % 25
        d = n // 10
        if d == 1:
            r += str(int(d)) + " dime \n"
        elif d > 1:
            r += str(int(d)) + " dimes \n"
        n = n % 10
        nk = n // 5
        if nk == 1:
            r += str(int(nk)) + " nickel \n"
        elif nk > 1:
            r += str(int(nk)) + " nickels \n"
        p = n % 5
        if p == 1:
            r += str(int(p)) + " penny \n"
        elif p > 1:
            r += str(int(p)) + " pennies \n"
        print(r)
        print("--------------------------------------- \n")

================ RESTART: C:\Optimal Payment.py ===============
The Optimal Way of Paying a Sum of US Dollars
pythonize.ir 	 Programmer: Mohammad Rajabpur
To exit the program, enter a negative amount
-------------------------------------------- 

n = 1399
$ 1399.0 =
13 hundred-dollar bills 
1 fifty-dollar bill 
2 twenty-dollar bills 
1 five-dollar bill 
2 two-dollar bills 

-------------------------------------------- 

n = 0.81
$ 0.81 =
3 quarters 
1 nickel 
1 penny 

-------------------------------------------- 

n = 0
$0 =
No bills and coins!
-------------------------------------------- 

n = 95378462103
$ 95378462103.0 =
953784621 hundred-dollar bills 
1 two-dollar bill 
1 one-dollar bill 

-------------------------------------------- 

n = -1
The program is terminated. Goodbye!