ISL 1991 Problem 18

Find the highest degree $k$ of $1991$ for which $1991^k$ divides the number $1990^{1991^{1992}} + 1992^{1991^{1990}}.$

Dataset text AI-MO AoPS. Quoted with source.

Solutions

No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.