output_description: Print the number of ways to move the pieces to achieve our objective, modulo
  998244353.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N A B
attempt: # F
  
problem_description: Statement
  
  We have two indistinguishable pieces placed on a number line. Both pieces are
  initially at coordinate 0. (They can occupy the same position.)
  
  We can do the following two kinds of operations:
  
    * Choose a piece and move it to the right (the positive direction) by 1.
    * Move the piece with the smaller coordinate to the position of the piece with the greater coordinate. If two pieces already occupy the same position, nothing happens, but it still counts as doing one operation.
  
  We want to do a total of N operations of these kinds in some order so that one
  of the pieces will be at coordinate A and the other at coordinate B. Find the
  number of ways to move the pieces to achieve it. The answer can be enormous,
  so compute the count modulo 998244353.
  
  Two ways to move the pieces are considered different if and only if there
  exists an integer i (1 \leq i \leq N) such that the set of the coordinates
  occupied by the pieces after the i-th operation is different in those two
  ways.
samples: [{"input": "5 1 3", "output": "4\n    \n\nShown below are the four ways to move the pieces, where (x,y) represents the\nstate where the two pieces are at coordinates x and y.\n\n  * (0,0)\u2192(0,0)\u2192(0,1)\u2192(0,2)\u2192(0,3)\u2192(1,3)\n  * (0,0)\u2192(0,0)\u2192(0,1)\u2192(0,2)\u2192(1,2)\u2192(1,3)\n  * (0,0)\u2192(0,0)\u2192(0,1)\u2192(1,1)\u2192(1,2)\u2192(1,3)\n  * (0,0)\u2192(0,1)\u2192(1,1)\u2192(1,1)\u2192(1,2)\u2192(1,3)\n\n* * *"}, {"input": "10 0 0", "output": "1\n    \n\n* * *"}, {"input": "10 4 6", "output": "197\n    \n\n* * *"}, {"input": "1000000 100000 200000", "output": "758840509"}]