#include<bits/stdc++.h>
#define ls x<<1
#define rs x<<1|1
#define ll long long
using namespace std;
const int N=1e5+10;
int n,bl[N],br[N];
struct node{
    int x,y;
}a[N];
pair<int,int> yl[N],yr[N],yy[N];
ll ans;
int op,val[N];
ll t1[N<<2],t2[N<<2],tag[N<<2];
void upd(int x,int k){t1[x]+=k;t2[x]+=k;tag[x]+=k;}
void pushdown(int x){if(tag[x]){upd(ls,tag[x]);upd(rs,tag[x]);tag[x]=0;}}
void pushup(int x){t1[x]=min(t1[ls],t1[rs]);t2[x]=min(t2[ls],t2[rs]);}
void build(int x,int l,int r){
    tag[x]=0;
    if(l==r){t1[x]=val[l]+br[l-1];t2[x]=val[l]+br[l-1]*2;return;}
    int mid=(l+r)>>1;
    build(ls,l,mid);build(rs,mid+1,r);
    pushup(x);
}
void modify(int x,int l,int r,int L,int R,int k){
    if(L>R) return;
    if(L<=l&&r<=R) return upd(x,k);
    int mid=(l+r)>>1;pushdown(x);
    if(L<=mid) modify(ls,l,mid,L,R,k);
    if(mid<R) modify(rs,mid+1,r,L,R,k);
    pushup(x);
}
int st1[N],tp1,st2[N],tp2;
void print(int x,int l,int r){
    if(l==r) {printf("%d ",t1[x]);return;}
    int mid=(l+r)>>1;
    print(ls,l,mid);print(rs,mid+1,r);
}
int main(){
    int T;scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        int nl=0,nr=0;ans=1e16;
        for(int i=1;i<=n;++i){
            scanf("%d%d",&a[i].x,&a[i].y);
            if(a[i].x<0) bl[++nl]=-a[i].x;
            if(a[i].x>0) br[++nr]=a[i].x;
        }
        sort(bl+1,bl+nl+1);sort(br+1,br+nr+1);
        nl=unique(bl+1,bl+nl+1)-bl-1;nr=unique(br+1,br+nr+1)-br-1;
        // printf("nl=%d nr=%d\n",nl,nr);
        for(int i=1;i<=n;++i){
            if(a[i].x<0)
                a[i].x=lower_bound(bl+1,bl+nl+1,-a[i].x)-bl,yl[a[i].x].first=max(yl[a[i].x].first,a[i].y),yl[a[i].x].second=min(yl[a[i].x].second,a[i].y);
            else if(a[i].x>0)
                a[i].x=lower_bound(br+1,br+nr+1,a[i].x)-br,yr[a[i].x].first=max(yr[a[i].x].first,a[i].y),yr[a[i].x].second=min(yr[a[i].x].second,a[i].y);
        }
        for(int i=nr;i;--i) yr[i].first=max(yr[i].first,yr[i+1].first),yr[i].second=min(yr[i].second,yr[i+1].second);
        val[nr+1]=0;
        // puts("yl:");
        // for(int i=1;i<=nl;++i) printf("%d %d\n",yl[i].first,yl[i].second);
        // puts("yr:");
        // for(int i=1;i<=nr;++i) printf("%d %d\n",yr[i].first,yr[i].second);
        tp1=tp2=0;
        for(int i=1;i<=nr;++i){
            val[i]=1ll*2*yr[i].first-yr[i].second;
            if(yr[i].first>yr[i+1].first) st1[++tp1]=i;
            if(yr[i].second<yr[i+1].second) st2[++tp2]=i;
        }
        build(1,1,nr+1);
            // print(1,1,nr+1);puts("");
        ans=min(ans,min(t1[1]+2*bl[nl],t2[1]+bl[nl]));
        for(int i=nl,ny1=0,ny2=0;i;--i){
            if(ny1<yl[i].first){
                for(;tp1&&yr[st1[tp1]].first<=yl[i].first;--tp1) modify(1,1,nr+1,st1[tp1]+1,nr+1,2*(yr[st1[tp1]].first-ny1)),ny1=yr[st1[tp1]].first;
                modify(1,1,nr+1,st1[tp1]+1,nr+1,2*(yl[i].first-ny1));
                ny1=yl[i].first;
            }
            // print(1,1,nr+1);puts("");
            if(ny2>yl[i].second){
                for(;tp2&&yr[st2[tp2]].second>=yl[i].second;--tp2) modify(1,1,nr+1,st2[tp2]+1,nr+1,ny2-yr[st2[tp2]].second),ny2=yr[st2[tp2]].second;
                modify(1,1,nr+1,st2[tp2]+1,nr+1,ny2-yl[i].second);
                ny2=yl[i].second;
            }
            // printf("%d %d\n",ny1,ny2);
            // printf("t: %d %d\n",t1[1],t2[1]);
            ans=min(ans,min(t1[1]+2*bl[i-1],t2[1]+bl[i-1]));
            // printf("%d %d\n",t1[1]+2*bl[i-1],t2[1]+bl[i-1]);
        }
        tp1=tp2=0;
        for(int i=1;i<=nr;++i){
            val[i]=1ll*yr[i].first-2*yr[i].second;
            if(yr[i].first>yr[i+1].first) st1[++tp1]=i;
            if(yr[i].second<yr[i+1].second) st2[++tp2]=i;
        }
        // puts("end 1");
        build(1,1,nr+1);
        // print(1,1,nr+1);puts("");
        ans=min(ans,min(t1[1]+2*bl[nl],t2[1]+bl[nl]));
        for(int i=nl,ny1=0,ny2=0;i;--i){
            if(ny1<yl[i].first){
                for(;tp1&&yr[st1[tp1]].first<=yl[i].first;--tp1) 
                    modify(1,1,nr+1,st1[tp1]+1,nr+1,yr[st1[tp1]].first-ny1),ny1=yr[st1[tp1]].first;
                modify(1,1,nr+1,st1[tp1]+1,nr+1,yl[i].first-ny1);
                ny1=yl[i].first;
            }
            // print(1,1,nr+1);puts("");
            if(ny2>yl[i].second){
                for(;tp2&&yr[st2[tp2]].second>=yl[i].second;--tp2) modify(1,1+1,nr+1,st2[tp2]+1,nr+1,2*(ny2-yr[st2[tp2]].second)),ny2=yr[st2[tp2]].second;
                modify(1,1,nr+1,st2[tp2]+1,nr+1,2*(ny2-yl[i].second));
                ny2=yl[i].second;
            }
            // printf("%d %d\n",ny1,ny2);
            // printf("t: %d %d\n",t1[1],t2[1]);
            ans=min(ans,min(t1[1]+2*bl[i-1],t2[1]+bl[i-1]));
        }
        for(int i=1;i<=nl;++i) yl[i]={0,0};
        for(int i=1;i<=nr;++i) yr[i]={0,0};
        printf("%lld\n",ans);
    }
    return 0;
}