C# program which accept one string and one integer?

Question

If string=aabbccc and Int 2

output=ccc ......It will remove aabb as their count match with enter int.

 

If string=aaabbccc and Int 3

output=bb

 

If string=aaabbccc and Int 1

output=aaabbccc output will be same as none of the character match with entered string.

 

 

If string=abc Int 1

output=  output will be empty as the as all character matched with entered string