#include <bits/stdc++.h>
using namespace std;

#define Int register int
#define MAXN 100005

template <typename T> inline void read (T &t){t = 0;char c = getchar();int f = 1;while (c < '0' || c > '9'){if (c == '-') f = -f;c = getchar();}while (c >= '0' && c <= '9'){t = (t << 3) + (t << 1) + c - '0';c = getchar();} t *= f;}
template <typename T,typename ... Args> inline void read (T &t,Args&... args){read (t);read (args...);}
template <typename T> inline void write (T x){if (x < 0){x = -x;putchar ('-');}if (x > 9) write (x / 10);putchar (x % 10 + '0');}

int t,n,x[MAXN],y[MAXN],cnt[MAXN];

signed main(){
    read (t);
    while (t --){
        memset (cnt,0,sizeof (cnt));
        read (n);int ans = 0;
        for (Int i = 1;i <= n;++ i){
            read (x[i],y[i]);
            if (x[i] == 1) cnt[y[i]] ++;
        } 
        for (Int i = 1;i <= n;++ i){
            if (x[i] == 2){
                int now = y[i] + (!cnt[y[i] + 1] ? 2 : 3);
                ans = max (ans,now);
            }
            else{
                int now = y[i] + 1;
                ans = max (ans,now);
            }
        }
        write (ans),putchar ('\n');
    }
    return 0;
}