Add one pair of brackets to the expression:

\[1 + 2 \times 3 + 4 \times 5 + 6\]

so that the resulting expression has a valid mathematical value. For example, \(1 + 2 \times (3 + 4 \times 5) + 6 = 53\). What is the largest possible value that one can make?

Let's think step by step and output the final answer within \boxed{}.
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