prog.cs(14,26): error CS1061: Type `System.Collections.Generic.Dictionary<int,double>' does not contain a definition for `Key' and no extension method `Key' of type `System.Collections.Generic.Dictionary<int,double>' could be found. Are you missing an assembly reference?
/usr/lib/mono/4.5/mscorlib.dll (Location of the symbol related to previous error)
Compilation failed: 1 error(s), 0 warnings