# What's so special about 1987?

$(m^{1987}-m+1987)^{m^{1987}-m+1987} = (n^{7891}-n+7891)^{n^{7891}-n+7891}$

Find the number of solutions to the Diophantine equation above?

Hint: Work in modular arithmetic using a small mod.

Details and Assumptions

If there are infinitely many solutions, input $$-1$$.

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