Please provide solution in following Question asked in an Online Assesment to my friend.

A driver want to manage his rides.he can either go for in-city ride or go for inter-city ride. Amount paid for both the rides are different on each day.
U can go for inter-city ride only if u did not go for any ride previous day. U can also choose for no ride a day.
Your task is to maximize driver's profit.

Input-
N = no.of days
Then city rideand inter-city ride"s salary for each day.
Cost of city ride always less than inter-city ride.
Ex n= 4
10 20
40 100
200 210
20 230