output_description: Print the number of the possible sequences of the colors of the balls after
  painting, modulo 10^9+7.
  
  * * *
input_description: The input is given from Standard Input in the following format:
  
      
      
      N K
attempt: print(1)
  
problem_description: Statement
  
  Snuke loves colorful balls. He has a total of N×K balls, K in each of his
  favorite N colors. The colors are numbered 1 through N.
  
  He will arrange all of the balls in a row from left to right, in arbitrary
  order. Then, for each of the N colors, he will paint the leftmost ball of that
  color into color 0, a color different from any of the N original colors.
  
  After painting, how many sequences of the colors of the balls are possible?
  Find this number modulo 10^9+7.
samples: [{"input": "2 2", "output": "4\n    \n\nThe following 4 sequences are possible:\n\n  * (0,1,0,2)\n  * (0,0,1,2)\n  * (0,2,0,1)\n  * (0,0,2,1)\n\n* * *"}, {"input": "3 1", "output": "1\n    \n\nThe following 1 sequence is possible:\n\n  * (0,0,0)\n\n* * *"}, {"input": "2 3", "output": "14\n    \n\n* * *"}, {"input": "2000 2000", "output": "546381702"}]