Splitting a string into multiple Arrays

For my program, the input from the user will be something like this:

{1,2,3} {1,2} {4,5,6}

There can be multiple { } with any number of ... numbers inside.

I already made a 2 dimensional array with an array for each sequence of numbers: {}

I am having troubling splitting them into their respective arrays so it will be something like this:

Array[0] = ["1","2","3"]    
Array[1] = ["1","2"]  
Array[2] = ["4","5","6"]  

How would i split it like that? i dont know if i can split this string into n number of strings since the number of sequences depends on user.