Consider a directed graph G$,$ where each edge is colored either red, white, or blue. A walk in G is called a French flag walk if its sequence of edge colors is red, white, blue, red, white, blue, and so on$.$ More formally, a walk v$\_(0),$v$\_(1),...,$v$\_($k$)$ is a French flag walk if$,$ for every integer i$,$ the edge $($v$\_($i$),$v$\_($i$+1))$ is red $($resp$.,$ white, blue$)$ if i mod $3=0($resp$.,1,2).$ Design a linear$-$time algorithm to find all nodes in G that can be reached from a given node s through a French flag walk.