Let A=\{1,2,3,4,5,6,7\}, and let N be the number of functions f from set A to set A such that f(f(x)) is a constant function. Find the remainder when N is divided by 1000 .
Let A=\{1,2,3,4,5,6,7\}, and let N be the number of functions f from set A to set A such that f(f(x)) is a constant function. Find the remainder when N is divided by 1000 .