#include "bits/stdc++.h"
using namespace std;


/* macro */
#define rep(i,a,b) for(int i=a;i<b;i++)
#define revrep(i,a,b) for(int i = a; i > b; i--)
#define int long long
#define exist(s,e) ((s).find(e)!=(s).end())
#define all(v) (v).begin(), (v).end()
#define each(s,itr) for(auto (itr) = s.begin(); (itr) != s.end(); (itr)++)
#define sum(v) accumulate(all(v), (0LL))


/* alias */
template<class T> using vec = vector<T>;
typedef vector<int> vi;
typedef pair<int, int> pi;


/* constant */
const int inf = pow(2, 62);
const int mod = 1e9 + 7;
int dx[8]={1,0,-1,0,-1,1,-1,1};
int dy[8]={0,1,0,-1,-1,-1,1,1};

/* io_method */
int input(){int tmp;cin >> tmp;return tmp;}
string raw_input(){string tmp;cin >> tmp;return tmp;}
string readline(){string s;getline(cin, s);return s;}
template<class T> void printx(T n){cout << n;}
template<class T, class U> void printx(pair<T, U> p){cout << "(" << p.first << "," << p.second << ")";}
template<class T> void printx(vector<T> v){cout << "{";rep(i,0,v.size()){printx(v[i]);if(i != v.size()-1)printx(",");}cout << "}";}
template<class T> void print(T n){printx(n);cout << endl;}
template<class T> void print(set<T> s){cout << "{";each(s, e){if(e != s.begin()) printx(",");printx(*e);}cout << "}" << endl;}
template<class T, class U> void print(map<T, U> mp){cout << "{";each(mp, e){cout << "(" << e -> first << "," << e -> second << ")";}cout << "}" << endl;}


/* general_method */
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }




/* main */


signed main(){

    cin.tie(0);
    ios::sync_with_stdio(false);

    int n = input();

    int val[n];
    int wei[n];

    rep(i,0,n){
        int v, w; cin >> v >> w;

        val[i] = v;
        wei[i] = w;
    }

    int dp[n + 1][100010];
    memset(dp, -1, sizeof(dp));
    dp[0][0] = 0;

    rep(i,0,n){
        rep(j,0,100010){
            if(dp[i][j] > -1){
                if(j + wei[i] <= 100000) chmax(dp[i + 1][j + wei[i]], dp[i][j] + val[i]);
                chmax(dp[i + 1][j], dp[i][j]);
            }
        }
    }

    rep(i,1,100010){
        chmax(dp[n][i], dp[n][i-1]);
    }

    int value = input();

    int left = lower_bound(dp[n] + 1, dp[n] + 100001, value) - dp[n];
    int right = upper_bound(dp[n] + 1, dp[n] + 100001, value) - dp[n];

    if(right == 100001){
        print("inf");
    }else{
        print(right - 1);
    }




    

    








    






    


    
    

    
    






    




    

    





    

   




    

    

    



    
    



    







    

    

    




    



    



    

 
    
    


    

    
   
    













}