The factorial "!" is defined for integers nn such that n!=n(n−1)(n−2)⋯1n! = n(n-1)(n-2) \cdots 1. For example, 5!=5⋅4⋅3⋅2⋅1=1205! = 5 \cdot 4 \cdot 3 \cdot 2 \cdot 1 = 120.

Find the last 44 digits of

1(1!)+2(2!)+3(3!)+…+2013(2013!).1(1!) + 2(2!) + 3(3!) + \ldots + 2013(2013!).

Source: Lexington Math Tournament

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