#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
//-------------------------------------------------------

ll ma[101010];
ll mi[101010];
int V,W,T;
int N;
void solve() {
	int i,j,k,l,r,x,y; string s;
	
	FOR(i,101000) ma[i]=-1LL<<30;
	ma[0]=mi[0]=0;
	cin>>N;
	int tot=0;
	FOR(i,N) {
		cin>>V>>W;
		tot+=W;
		for(j=100000;j>=W;j--) ma[j]=max(ma[j],ma[j-W]+V);
	}
	
	cin>>T;
	FOR(i,tot+1) if(i) ma[i]=max(ma[i],ma[i-1]);
	
	FOR(i,tot+1) {
		if(ma[i]==T) {
			if(i==0) i++;
			cout<<i<<endl;
			break;
		}
	}
	if(ma[tot]==T) {
		cout<<"inf"<<endl;
	}
	else {
		for(i=tot-1;i>=0;i--) if(ma[i]==T) {
			cout<<i<<endl;
			break;
		}
	}
	
	
	
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n';
	FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	solve(); return 0;
}