#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

template<class Type>
inline void R(Type &x) {
    int c = getchar();
    bool neg = 0;
    for (; c < 48 || c > 57; c = getchar())if (c == '-')neg = true;
    for (x = 0; c > 47 && c < 58; x = (Type) 10 * x + c - 48, c = getchar());
    if (neg)x = -x;
}

int n, s[100010];

int main() {
    int T;
    R(T);
    while (T--) {
        R(n);
        for (int i = 0; i <= 100000; ++i)
            s[i] = 0;
        int mxy = 0;
        for (int i = 1; i <= n; ++i) {
            int x, y;
            R(x);
            R(y);
            if (s[y] == 0)
                s[y] = x;
            else
                s[y] = 3;
            mxy = max(mxy, y);
        }
        int flag = 0, left_go = 0, right_stop = 0, right_go = 0;
        for (int k = 1; k <= mxy; ++k) {
            if (s[k] == 2 || s[k] == 3)
                left_go = k + 3;
            if (s[k] == 1) {
                right_stop = k + 2;
                if (flag == 3 || flag == 2)
                    right_go = max(k + 1, left_go);
                if (flag == 1)
                    right_go = max(k + 1, right_go);
                if (flag == 0)
                    right_go = k + 1;
            }
            flag = s[k];
        }
        if (flag == 3)
            printf("%d\n", mxy + 2);
        if (flag == 2)
            printf("%d\n", mxy + 2);
        if (flag == 1)
            printf("%d\n", min(right_stop, right_go));
    }
    return 0;
}