Author/Opus: This is the 1st puzzle from guest contributor Gaurav Kumar Jain. You can find more puzzles from Gaurav on the blog Life in Sudoku.
Rules: Standard Sudoku rules. Also, digits in circles must be odd and digits in squares must be even.
Answer String: Enter the 1st row from left to right, followed by a comma, followed by the 6th row from left to right.
Time Standards (highlight to view): Grandmaster = 2:15, Master = 3:15, Expert = 6:30