MATLAB: How to separate element from cell

Question

U=SI

U =

1×2 cell array

[1×2 double] [1×2 double]

U{1}

ans =

1 2

>> U{2}

ans =

2 3

My question is: how to separate element of cell, and put them in vector:

vect=[ 1 2 3]

Answer 1

unique([U{:}])