Show total only last month

Hi,

I need help

I need show in my gauge the value just of the LASTMONTH

When I use the expression:

= CALCULATE([VALUE];DATEADD(Tempo[Date]; -1; MONTH))

My result its total, its sum all values in rows, but I need just the last month

In this example:

month      values

2016-1     1

2016-2     5

2016-10     10

2016-10     10

So I need return the 20 in my result