B'zscoder has a deck of n+m custom-made cards, which consists of n cards labelled from 1 to n and m jokers. Since zscoder is lonely, he wants to play a game with himself using those cards. Initially, the deck is shuffled uniformly randomly and placed on the table. zscoder has a set S which is initially empty. Every second, zscoder draws the top card from the deck. What is the expected number of seconds before the game ends? We can show that the answer can be written in the form frac{P}{Q} where P, Q are relatively prime integers and Q neq 0 bmod 998244353 . Output the value of (P cdot Q^{-1}) modulo 998244353 . The only line of the input contains two integers n and m ( 1 <= n, m <= 2 cdot 10^{6} ). Output a single integer, the value of (P cdot Q^{-1}) modulo 998244353 . For the first sample, it can be proven that the expected time before the game ends is 5 seconds. For the second sample, it can be proven that the expected time before the game ends is frac{28}{3} seconds. '...