Commodities in cartons to be shifted from Lorry to Tata Eicher. When commodities in a lorry is shifted, it fills two Tata Eicher, and still, 13 cartons of commodities remain outside. If the number of cartons in Tata Eicher is taken as '\(a\)' what is the number of cartons in the Lorry?
The number of cartons in the Lorry \(=\) .
[Note: Insert variable first and then followed by number.]