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while num != "":
number = float(num)
sum += number
num = input("Enter a number or just hit ENTER to quit: ")
print("The sum is", sum)
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n = input("Enter Number to calculate sum")
n = int (n)
sum = 0
for num in range(0, n+1, 1):
sum = sum+num
print("SUM of first ", n, "numbers is: ", sum )