Abhishar and Combinatorics

Abhishar was doing some calculations on his computer and was writing the results on a paper. While writing on the paper he forgot to write the inputs. He was just writing down the output. He was doing combinatorics and was calculating nCk which is equal to N! / ( (N-K)! * K! ). So Abhishar has got the final output of nCk as res, but now he wants to know all the values of N and K that would have e