N=int(input())
L=[list(map(int,input().split())) for i in range(N)]
V=int(input())

DP=[0]*100002

for v,w in L:
    for i in range(100001,-1,-1):
        if i+w<100002:
            DP[i+w]=max(DP[i+w],DP[i]+v)

flag=0
for i in range(1,100002):
    if flag==0 and DP[i]==V:
        print(i)
        flag=1
    if flag==1:
        if DP[i]!=V:
            print(i-1)
            break
else:
    print("inf")