N = int(input()) VW = [list(map(int, input().split())) for _ in range(N)] V = int(input()) DP = [0]*(100010) for v,w in VW: for i in reversed(range(100010)): if DP[i]>0: DP[i+w]=max(DP[i+w],DP[i]+v) DP[w]=max(DP[w],v) for i in range(1,100010): DP[i]=max(DP[i],DP[i-1]) mi=0 ma=0 for i in range(100010): if DP[i]==V and mi==0: mi=i if DP[i]==V: ma=i print(max(mi,1)) if ma==100009: print('inf') else: print(ma)