#include <cstdio>
#include <algorithm>

inline int Max(const int &x, const int &y) {
    return x > y ? x : y;
}

inline int input() {
    static int p;
    scanf("%d", &p);
    return p;
}
// inline double inputf() {
//     static double p;
//     scanf("%lf", &p);
//     return p;
// }

int main() {
    int mx[3];
    for (int T = input(); T; --T) {
        const int n = input();
        mx[1] = mx[2] = 0;
        for (int i = 1; i <= n; ++i) {
            const int x = input(), y = input();
            mx[x] = Max(mx[x], y);
        }
        if (mx[2] + 2 <= mx[1] or mx[2] == 0) printf("%d\n", 1 + mx[1]);
        else if (mx[2] >= mx[1]) printf("%d\n", 2 + mx[2]);
        else printf("%d\n", 2 + mx[1]);
    }

    return 0;
}