# Prompt user for a decimal number
decimal = int(input("Enter a decimal number: "))

# Convert decimal to binary
binary = bin(decimal)

# Convert decimal to hexadecimal
hexadecimal = hex(decimal)

# Display the results
print("Binary:", binary)
print("Hexadecimal:", hexadecimal)

primes=[]
products=[]

def prime(num):
    if num > 1:
        for i in range(2,num):
            if (num % i) == 0:
                return False
        else:
            primes.append(num)
            return True

for n in range(30,1000):
    if len(primes) >= 20:
        break;
    else:
        prime(n)

for previous, current in zip(primes[::2], primes[1::2]):
    products.append(previous * current)
    
print (products)

filename = "data.txt"
data = "Hello, World!"

with open(filename, "a") as file:
    file.write(data)

print(“Hello World”)