'''

global F # a global dp table for knapsack

if F[i][j] < 0:

if j < wt[i - 1]:

val = MF_knapsack(i - 1,wt,val,j)

else:

val = max(MF_knapsack(i - 1,wt,val,j),MF_knapsack(i - 1,wt,val,j - wt[i - 1]) + val[i - 1])

F[i][j] = val

dp = [[0 for i in range(W+1)]for j in range(n+1)]

for i in range(1,n+1):

for w in range(1,W+1):

if(wt[i-1]<=w):

dp[i][w] = max(val[i-1]+dp[i-1][w-wt[i-1]],dp[i-1][w])

else:

dp[i][w] = dp[i-1][w]