from re import split
n, x = map(int, input().split())
list1=list(map(int, input().split()))
list2=list(map(int, input().split()))
totoal_cost=0
for i in range(n):
    if list1[i] < list2[i]:
        totoal_cost += list1[i]
    else:
        totoal_cost += list2[i]
if totoal_cost> x:
    print(x)
else:
    print(totoal_cost)