11331

#include <iostream>
using namespace std;

int main() {
    int n;
    cin >> n; // кол-во
    int x,y;
    int min_r = 10001;
    int sum = 0;

    for(int i = 0; i < n; ++i) {
        cin >> x >> y;
        if (x > y) {
            sum += x;
            if (x - y < min_r && (x - y) % 2 != 0) {
                min_r = x - y;
            }
        }
        else {
            sum += y;
            if (y - x < min_r && (y - x) % 2 != 0)
                min_r = y - x;
        }
    }

    if(sum % 2 == 0) {
        if(min_r != 10001) {
            sum -= min_r;
            cout << sum << endl;
        }
        else {
            cout << "0" << endl;
        }
    }
    else {
        cout << sum << endl;
    }
    return 0;
}