Getting First Record from DAX Measure

I have a report that includes a measure [ConsecutiveDaysMeasure]. My objective is to create a Y/N flag to identify the first date or dates where this measure becomes greater than or equal to 4 (evaluating each student individually). Looking at an individual row, the logic would be, if the [ConsecutiveDaysMeasure] value in this row is greater than or equal to 5 AND (either there is NO prior [ConsecutiveDayMeasure] for the student OR the prior [ConsecutiveDayMeasure] for the student is NOT greater than or equal to 5), then flag "Y", else "N". On the image, the arrow represent the rows which should be flagged with a "Y".

Thanks,

John