N = int(input())
item = [list(map(int, input().split())) for _ in range(N)]
V = int(input())
dp = [[0]*(10**5+1) for _ in range(N+1)]
sm_v, sm_w = 0, 0
for i in range(1, N+1):
    v, w = item[i-1]
    sm_v += v
    sm_w += w
    for j in range(10**5+1):
        if j>=w:
            dp[i][j] = max(dp[i-1][j-w]+v, dp[i][j])
        dp[i][j] = max(dp[i][j], dp[i-1][j])

for i in range(1,10**5+1):
    if dp[-1][i] == V:
        print(i)
        break
if dp[-1][sm_w] == V:
    print('inf')
else:
    for i in range(10**5, 0, -1):
        if dp[-1][i] == V:
            print(i)
            break