#include <iostream>
#include <utility>
#include <tuple>
#include <string>
#include <cstdint>
#include <vector>
#include <array>
#include <queue>
#include <set>
#include <map>
#include <algorithm>
#include <cmath>
#include <cassert>
using namespace std;
using i64 = int64_t;
i64 n;
int main() {
    cin >> n;
    i64 sa = 0, sb = 0;
    for (int i = 0; i < n - 1; ++i) {
        i64 a, b;
        cin >> a >> b;
        sa += a;
        sb += b;
    }
    i64 ans = min(sa, sb) + 1;
    cout << ans << endl;
    return 0;
}