Fortran- f90檔IF迴圈問題求助

我寫了一個帶有IF迴圈的f90檔，在編譯時出現了以下錯誤訊息，希望有人能幫我解惑：

INTEGER HG
1
Error: Unexpected data declaration at (1)

IF HG>0
1
Error: Unclassifiable statement at (1)

ELSE
1
Error: Unexpected ELSE statement at (1)

END IF
1
Error: Expecting END PROGRAM statement at (1)

DO p=1,5
1
Warning:Deleted feature: Loop variable at (1) must be integer

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