#include <bits/stdc++.h>
#define file(name) freopen(name".inp" , " r " , stdin);freopen(name".out" , " w " , stdout);
#define faster ios_base :: sync_with_stdio(false) ; cin.tie(0) ; cout.tie(0) ;
#define pii pair < int , int >
#define fi first
#define se second
#define mii map< int , int>
#define reset(a,val) memset(a ,val , sizeof(a) )
#define count_bit(i) __builtin_popcountll(i)
#define mask(i) ((1LL << (i)))
#define status(x, i) (((x) >> (i)) & 1)
#define set_on(x, i) ((x) | mask(i))
#define set_off(x, i) ((x) & ~mask(i))
#define endl '\n'
#define ll long long
#define int ll
const int maxn = 1e6 + 6;
const int mod= 1e9 + 7;
const ll INFLL= 3e18 + 5;
const int INF = 1e9 + 5 ;
const int LOG = 20 ;
template <class T> inline T sqr(T x) { return x * x; };
template <class T> inline int Power(T x, int y)
{ if (!y) return 1; if (y & 1) return sqr(Power(x, y / 2)) % mod * x % mod; return sqr(Power(x, y / 2)) % mod; }
template<class T> bool minimize(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template<class T> bool maximize(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
inline int gcd(int x, int y)
{ return y ? gcd(y , x % y) : x;}
inline int lcm(int x, int y) { return x * y / gcd(x, y); }
using namespace std;
int k , n;
int dist = 0;
vector<pii> path;
// sub1 2
int calc(int x)
{
int res = 0;
for (int i = 0 ; i < path.size() ; ++i)
res += (abs(path[i].fi - x) + abs(path[i].se - x));
return res;
}
void solve1()
{
vector<int> a;
for (int i = 0 ; i < path.size() ; ++i)
a.push_back(path[i].fi) , a.push_back(path[i].se);
sort(a.begin() ,a.end());
int k = (a.size() + 1) / 2 - 1;
cout << dist + min(calc(a[k]) , min(calc(a[k - 1]) , calc(a[k + 1]))) << endl;
// cout << a[k] << " " << calc(a[k]) << endl;
}
//----------------------------------------------------------------------------------------------
// sub 3 4 5
priority_queue<int , vector<int> , less<int>> low;
priority_queue<int , vector<int> , greater<int>> up;
int sum_low = 0;
int sum_up = 0;
int f[maxn];
void INSERT(int val)
{
int a = (low.empty() ? INF : low.top());
if (a < val)
{
up.push(val);
sum_up += val;
}
else
{
low.push(val);
sum_low += val;
}
if (up.size() + 1 < low.size())
{
sum_low -= low.top();
sum_up += low.top();
up.push(low.top());
low.pop();
}
if (low.size() < up.size())
{
sum_up -= up.top();
sum_low += up.top();
low.push(up.top());
up.pop();
}
}
void solve2()
{
sort(path.begin() , path.end() , [&](pii a , pii b)
{
return a.fi + a.se < b.fi + b.se;
});
sum_low = 0;
sum_up = 0;
for (int i = 0 ; i < path.size() ; ++i)
{
INSERT(path[i].fi);
INSERT(path[i].se);
f[i] = sum_up - sum_low;
}
sum_low = 0;
sum_up = 0;
while (up.size()) up.pop();
while (low.size()) low.pop();
int ans = f[path.size() - 1];
for (int i = path.size() - 1 ; i >= 0 ; --i)
{
INSERT(path[i].fi);
INSERT(path[i].se);
minimize(ans , sum_up - sum_low + f[i - 1]);
}
cout << ans + dist << endl;
}
void solve()
{
cin >> k >> n ;
for (int i = 1 ; i <= n; ++i)
{
char a , b ; int x , y ; cin >> a >> x >> b >> y;
if (a == b) dist += abs(x - y);
else path.push_back({x , y});
}
dist += path.size();
if (k == 1) solve1();
if (k == 2) solve2();
}
int32_t main()
{
faster;
// file("txt");
// int t ; cin >> t ; while (t--)
solve();
return 0;
}
