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reference_mystery_xa

Language/Type: Python parameters reference semantics

When the main function below is called, the following code produces 4 lines of output. Write each line of output below as it would appear on the console.

null 
def mystery(x, a):
    x = x + 1
    a[x] = a[x] + 1
    print(x, a)

def main():
    x = 0
    a = [0, 0, 0, 0]
    x = x + 1
    mystery(x, a)
    print(x, a)
    x = x + 1
    mystery(x, a)
    print(x, a)

main()
line 1
line 2
line 3
line 4

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