#include <bits/stdc++.h>

int ri() {
	int n;
	scanf("%d", &n);
	return n;
}

int main() {
	int n = ri();
	n--;
	if (n == 1) {
		std::cout << 1 << std::endl;
		return 0;
	}
	int a[n], b[n];
	for (int i = 0; i < n; i++) a[i] = ri(), b[i] = ri();
	int a_min = 0;
	int b_min = 0;
	for (int i = 0; i < n; i++) {
		int a_sum = 0, b_sum = 0;
		for (int j = 0; j < n; j++) {
			if (i == j) continue;
			a_sum += a[j];
			b_sum += b[j];
		}
		a_min += std::min(a[i], b_sum);
		b_min += std::min(b[i], a_sum);
	}
	a_min = std::min(a_min, std::accumulate(b, b + n, 0));
	b_min = std::min(b_min, std::accumulate(a, a + n, 0));
	std::cout << std::min(a_min, b_min) + 1 << std::endl;
	
	return 0;
}