problem684.ijs


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modn =: 1000000007

S =: {{
	t =. <.y%9
	k =. 9|y
	pow10 =. 10 modn&|@^t NB. This is effective in J for calculating 10^t mod modn
	(6+y)-~pow10*+/6,k,>:i.k
}}

fib =: {{
	if. y < 2 do.
		y
	else.
		(fib y-2)+(fib y-1)
	end.
}} M.

problem684 =: modn|+/S@fib"0 x:2+i.89