How do i make 3 column to arrange in 1?

I have 3 column, i need to make one column,

Check image i have set manual for first 2 row to 1 column. What I want is get one list for 3 column.I have tried Transpose but it just transfer column to row line.

Transpose works for one row to one column i have to make manually for each row. but need it for whole.

How do i make 3 column to arrange in 1?

Using TOCOL to arrange 3 columns into one

You can use the TOCOL function to accomplish this.

Formula

=TOCOL(A1:C)

Sample Output

References: TOCOL function