#include <stdio.h>
#include <algorithm>

int n;

void solve(){
    scanf("%d",&n);
    int mx[2]={0};
    for(int i=1,id,p;i<=n;i++){
        scanf("%d%d",&id,&p);
        mx[id-1] = std::max(mx[id-1],p);
    }
    if(mx[1]==0){
        printf("%d\n",mx[0]+1);
        return;
    }
    if(mx[0]==0){
        printf("%d\n",mx[1]+2);
        return;
    }
    if(mx[1]>=mx[0]) printf("%d\n",mx[1]+2);
    else printf("%d\n",std::max(mx[0]+1,mx[1]+3));
}

int main(){
    int T; scanf("%d",&T);
    while(T--) solve();
}