s = list(map(int,input().split(" "))) n = s[0] cost1 = s[1] cost = 0 mark1 = list(map(int,input().split(" "))) mark2 = list(map(int,input().split(" "))) for i in range(n): c = min(mark1[i],mark2[i]) cost+=c ans = min(cost1,cost) print(ans)