#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
using namespace std;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v)) cerr << ", ";
  _print(v...);
}
const long long int MOD = 1e9 + 7;
const long long int INF = 1e18;
const long long int maxn = 1e6 + 4;
void solve() {
  int n;
  cin >> n;
  vector<int> v2;
  vector<int> v1;
  for (int i = 0; i < n; i++) {
    int a, w;
    cin >> a >> w;
    if (a == 1) {
      v1.push_back(w);
    } else
      v2.push_back(w);
  }
  sort((v1).begin(), (v1).end(), greater<int>());
  sort((v2).begin(), (v2).end(), greater<int>());
  for (int width = 1; width <= 2 * n; width++) {
    for (int twos = 0; twos <= v2.size(); twos++) {
      if (width - 2 * twos > (int)v1.size() || width - 2 * twos < 0) continue;
      int total_width = 0;
      for (int ones = width - 2 * twos; (ones >= 0) && (ones < v1.size());
           ones++) {
        total_width += v1[ones];
      }
      for (int ts = twos; ts < v2.size(); ts++) {
        total_width += v2[ts];
      }
      if (total_width <= width) {
        cout << width;
        return;
      }
    }
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  solve();
}
