#define _CRT_SECURE_NO_WARNINGS
#include <string>
#include <vector>
#include <algorithm>
#include <numeric>
#include <set>
#include <map>
#include <queue>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <cctype>
#include <cassert>
#include <limits>
#include <functional>
#include <bitset>
#define rep(i,n) for(int (i)=0;(i)<(int)(n);++(i))
#define rer(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i))
#define reu(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i))
#if defined(_MSC_VER) || __cplusplus > 199711L
#define aut(r,v) auto r = (v)
#else
#define aut(r,v) typeof(v) r = (v)
#endif
#define each(it,o) for(aut(it, (o).begin()); it != (o).end(); ++ it)
#define all(o) (o).begin(), (o).end()
#define pb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))
#define mset(m,v) memset(m,v,sizeof(m))
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL
using namespace std;
typedef vector<int> vi; typedef pair<int,int> pii; typedef vector<pair<int,int> > vpii;
typedef long long ll; typedef vector<long long> vl; typedef pair<long long,long long> pll; typedef vector<pair<long long,long long> > vpll;
typedef vector<string> vs; typedef long double ld;
template<typename T, typename U> inline void amin(T &x, U y) { if(y < x) x = y; }
template<typename T, typename U> inline void amax(T &x, U y) { if(x < y) x = y; }

int main() {
	int N;
	scanf("%d", &N);
	//F = 40000 (十分に大きな適当な値)
	//duration[i] = F - T[i] + 1
	//refuel[i]   = (F - T[i] + 1) - V[i]
	//とすると
	//<http://apps.topcoder.com/wiki/display/tc/SRM+610>
	//のAlbertoTheAviatorと同じになる。
	int F = 40000;
	vector<pii> v(N);
	rep(i, N) {
		int V, T;
		scanf("%d%d", &V, &T);
		int duration = F - T + 1, refuel = (F - T + 1) - V;
		v.push_back(mp(refuel, duration));
	}
	sort(all(v), greater<pii>());
	vector<bool> dp(F+1, false);
	dp[F] = true;
	rep(i, N) {
		int refuel = v[i].first, duration = v[i].second;
		for(int j = duration; j <= F; ++ j) if(dp[j]) {
//			cerr << i << ", " << F - j << endl;
			int nj = j - duration + refuel;
			if(j <= nj) cerr << "err" << endl;
			dp[nj] = true;
		}
	}
	int ans = 0;
	rer(i, 0, F) if(dp[i])
		amax(ans, F - i);
	printf("%d\n", ans);
	return 0;
}