#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;

void read(int &x) {
    x = 0; char c = getchar();
    while (c < '0' || c > '9') c = getchar();
    while (c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
}

const int N = 1e5 + 100;

int n;
int aa[N], bb[N];
int vis[N];

int main() {
    int T;
    read(T);
    while (T--) {
        read(n);
        int ans = 0;
        for (int i = 1; i <= n; i++) {
            read(aa[i]); read(bb[i]);
            if (aa[i] == 1) {
                vis[bb[i]] = true;
                ans = max(ans, bb[i] + 1);
            }
        }
        for (int i = 1; i <= n; i++) {
            if (aa[i] == 2) {
                if (!vis[bb[i] + 1]) {
                    vis[bb[i] + 1] = true;
                    ans = max(ans, bb[i] + 2);
                }
                else {
                    ans = max(ans, bb[i] + 3);
                }
            }
        }
        printf("%d\n", ans);
        for (int i = 1; i < N; i++) vis[i] = false;
    }
    return 0;
}