output_description: Print the number of strings of length N that satisfy the following conditions,
  modulo 10^9+7.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
attempt: XAA = 1
  XAT = 1
  XAG = 1
  XAC = 1
  XTA = 1
  XTT = 1
  XTG = 1
  XTC = 1
  XGA = 1
  XGT = 1
  XGG = 1
  XGC = 1
  XCA = 1
  XCT = 1
  XCG = 1
  XCC = 1
  m = 1000000007
  N = int(input())
  
  for i in range(N - 2):
      XAA, XAT, XAG, XAC, XTA, XTT, XTG, XTC, XGA, XGT, XGG, XGC, XCA, XCT, XCG, XCC = (
          (XAA + XTA + XGA + XCA) % m,
          (XAA + XTA + XGA + XCA) % m,
          (XAA + XTA + XGA + XCA) % m,
          (XAA + XTA + XCA) % m,
          (XAT + XTT + XGT + XCT) % m,
          (XAT + XTT + XGT + XCT) % m,
          (XAT + XTT + XGT + XCT) % m,
          (XAT + XTT + XGT + XCT) % m,
          (XAG + XTG + XGG) % m,
          (XAG + XTG + XGG + XCG) % m,
          (XAG + XTG + XGG + XCG) % m,
          (XTG + XGG + XCG) % m,
          (XAC + XTC + XGC + XCC) % m,
          (XAC + XTC + XGC + XCC) % m,
          (XTC + XGC + XCC) % m,
          (XAC + XTC + XGC + XCC) % m,
      )
  
  print(
      (
          XAA
          + XAT
          + XAG
          + XAC
          + XTA
          + XTT
          + XTG
          + XTC
          + XGA
          + XGT
          + XGG
          + XGC
          + XCA
          + XCT
          + XCG
          + XCC
      )
      % m
  )
  
problem_description: Statement
  
  You are given an integer N. Find the number of strings of length N that
  satisfy the following conditions, modulo 10^9+7:
  
    * The string does not contain characters other than `A`, `C`, `G` and `T`.
    * The string does not contain `AGC` as a substring.
    * The condition above cannot be violated by swapping two adjacent characters once.
samples: [{"input": "3", "output": "61\n    \n\nThere are 4^3 = 64 strings of length 3 that do not contain characters other\nthan `A`, `C`, `G` and `T`. Among them, only `AGC`, `ACG` and `GAC` violate\nthe condition, so the answer is 64 - 3 = 61.\n\n* * *"}, {"input": "4", "output": "230\n    \n\n* * *"}, {"input": "100", "output": "388130742\n    \n\nBe sure to print the number of strings modulo 10^9+7."}]