#include <iostream>
#include <vector>
#include <algorithm>

typedef long long ll;

using namespace std;

const ll inf = 1e11 + 1;

int main() {
    int n;
    cin >> n;
    vector<pair<int, int>> nums(n);
    for (auto &it : nums) {
        cin >> it.first >> it.second;
    }

    vector<vector<ll>> dp(n, vector<ll>(16, inf));
    dp[0][nums[0].first % 16] = nums[0].first;
    dp[0][nums[0].second % 16] = nums[0].second;

    for (int i = 1; i < n; ++i) {
        int num1 = nums[i].first, num2 = nums[i].second;
        int r1 = num1 % 16, r2 = num2 % 16;
        for (int k = 0; k < 16; ++k) {
            if (k >= r1) {
                dp[i][k] = min(dp[i][k], dp[i - 1][k - r1] + num1);
            } else {
                dp[i][k] = min(dp[i][k], dp[i - 1][16 - r1 + k] + num1);
            }
            if (k >= r2) {
                dp[i][k] = min(dp[i][k], dp[i - 1][k - r2] + num2);
            } else {
                dp[i][k] = min(dp[i][k], dp[i - 1][16 - r2 + k] + num2);
            }
        }
    }

    cout << dp[n - 1][15] << '\n';
}