dynamic programming question similar to traveling salesman in python

So I just started exploring dynamic programming a little bit more in depth and I have come across a question which I've been unable to solve for a while now. I would greatly appreciate any help with it.

Find the maximum revenue for a salesman who knows how much revenue he will get in each city per day, given he is free for len(days_travel) days;

The input list revenue shows the revenue he will get on a particular day at a particular city (eg. revenue[0][1] = 2: day 0 and at city 'b') and travel days is the number of days he requires to travel from one city to the other (eg. days_travel[2][1] = 2 days is required to move from city c to city b and start is the city he starts in (at day 0)

the salesman can decide whether he will stay and sell in that city and earn revenue[day][city] or travel to another city from for 'x' number of days: So he will be on day + days_travel[start_city][to_city] day

Ex. (start = 1)
    #      city: a  b  c  # day:
    revenue = [[1, 2, 1],   # 0
               [3, 3, 1],   # 1
               [1, 1, 100]] # 2

    #         city:  a   b   c    # city:
    days_travel  = [[0,  1,  1],  # a
                   [ 1, 0,  1],  # b
                   [ 1,  2, 0]]  # c
max revenue = 102

Path:

1. Start at city 'b' on day 0, sell there, and earn 2
2. Now at day 1, travel to city c in the morning
3. Now at day 2, arrives at city C in the morning, work there and earn 100

My step:

Performed Floyd Warshall algorithm to days_travel, to find the shortest days from one city to the other, which using example above, results in the same matrix (but definitely can be different in others)

def floyd_warshall(days_travel):
    nV = len(G)
    # Adding vertices individually
    for k in range(nV):
        for i in range(nV):
            for j in range(nV):
                G[i][j] = min(G[i][j], G[i][k] + G[k][j])

which gives me ->

    #         city:  a   b   c    # city:
    days_travel  = [[0,  1,  1],  # a
                   [ 1, 0,  1],   # b
                   [ 1,  2, 0]]   # c

I then thought about looping through everything and using max() but doesn't work

for x in range(len(days_travel)):
   for y in range(len(days_travel)):
      for day in range(len(revenue)):

I would appreciate some help with this. Thanks

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