#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define MAX 100100
#define pii pair<int,int>
#define pll pair<ll,ll>
#define fi first
#define se second
#define all(a) (a).begin(),(a).end()
#define __buitin_popcount __builtin_popcountll
#define BIT(x,i) (((x)>>(i))&1ll)
#define MASK(i) (1ll<<(i))
// removed: #define left __left
// removed: #define right __right
template<class X,class Y> bool maximize(X &x,Y y)
{
if(x<y)
{
x=y;
return 1;
}
return 0;
}
template<class X,class Y> bool minimize(X &x,Y y)
{
if(y<x)
{
x=y;
return 1;
}
return 0;
}
const int inf=1e9+412009;
const ll INF=2e18+412009;
struct POINT
{
int x,y;
int id;
void input(int i=0)
{
cin>>x>>y;
id=i;
}
bool operator < (POINT other) const
{
return x==other.x ? y<other.y : x<other.x;
}
};
double LEN(POINT a,POINT b)
{
return abs(a.x-b.x)+abs(a.y-b.y);
}
struct RECT
{
int top=0,bot=0;
int L=0,R=0;
int id;
void input(int i=0)
{
id=i;
int x,y,u,v;
cin>>x>>y>>u>>v;
top=max(y,v);
bot=min(y,v);
R=max(x,u);
L=min(x,u);
}
bool operator < (RECT other) const
{
return L<other.L;
}
};
POINT T;
int n;
RECT a[MAX];
void nhap()
{
T.input(1);
int tmp;
cin>>tmp;
for(int i=1;i<=tmp;i++)
{
RECT vl; vl.input();
if(T.x<=vl.R) continue;
a[++n]=vl;
}
}
ll dist[MAX][2];
pii trace[MAX][2];
set<pii> s;
void solve()
{
memset(dist,0x3f,sizeof(dist));
sort(a+1,a+n+1);
s.insert({0,0});
dist[0][0]=0;
for(int i=1;i<=n;i++)
{
for(auto it=s.lower_bound({a[i].bot,-inf}); it!=s.end() && it->fi<=a[i].top; )
{
int id=abs(it->se), type=it->se>0;
if(minimize(dist[i][0], a[i].L - a[id].L + abs(a[i].bot-1-it->fi)+ dist[id][type])) trace[i][0]=*it;
if(minimize(dist[i][1], a[i].L - a[id].L + abs(a[i].top+1 - it->fi) + dist[id][type])) trace[i][1]=*it;
auto it1=it;
++it;
s.erase(it1);
}
if(dist[i][0]<INF) s.insert({a[i].bot-1,-i});
if(dist[i][1]<INF) s.insert({a[i].top+1,i});
}
ll ans=INF;
for(pii it:s)
{
int id=abs(it.se), type=it.se>0;
if(minimize(ans, dist[id][type] + abs(it.fi - T.y) + abs(a[id].L - T.x))) trace[n+1][0]=it;
}
cout<<ans<<'\n';
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr); cout.tie(nullptr);
nhap();
solve();
return 0;
}
