How to link SPRINT to test case automatically while importing?

[LALITHA]

i am trying to upload the test cases to using JAR[zfj-importer] file. But i am getting below error for SPRINT.

Unable to add testcase ending at rowNumber - 6. Error:Unexpected response code: 400
{"errorMessages":["Number value expected as the Sprint id."],"errors":{}} 

Kindly provide resolution