Time limit: 1 second Memory limit: 256 megabytes ---------- Valad has a row of roses, each of which wilts at the end of every month and re-blooms. Each time it re-blooms, it can be either white or black. Valad, who knows his roses well, knows that if, after the end of a period (the period refers to a number of consecutive months), the number of times a rose has bloomed white is even, that rose is "barren" (unblessed) and must be picked. For example, if Valad has 2 roses and considers them for 3 months, and the following situation occurs (referencing the visual data implied by the context): [The accompanying image describes the state over 3 months] In this case, the first rose was white two times, which is an even number, so the first rose is barren and must be picked. However, the second rose was white only once, which is an odd number, so it is a good (blessed) rose. Now, you are given the number of months in the period and the color of each rose in each month. You must determine whether each rose is blessed or not at the end of the period. # Input The first line gives you $n$, the number of Valad's roses, followed by $m$, the number of months in the period. In the $i$-th of the next $m$ lines, a string of length $n$ consisting of `B` and `W` is given, where the $j$-th element corresponds to the value located at the intersection of the $i$-th row (month) and the $j$-th column (rose). `W` means White. `B` means Black. $$1 \leq n, m \leq 20$$ # Output In the output, you are asked to print a row of $n$ characters. For every rose that has been white an even number of times, print the character `B` (for Barren). For the rest of them (those white an odd number of times), print the character `F` (for Flourishing/Good). # Example ## Sample Input 1 ``` 3 2 WBW BBW ``` ## Sample Output 1 ``` FBB ```