#include<bits/stdc++.h>
#define X first
#define Y second
#define all(x) begin(x), end(x)
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define FORD(i, b, a) for(int i = (b); i >= (a); i--)
#define REP(i, a, b) for (int i = (a); i < (b); i++)
#define mxx max_element
#define mnn min_element
#define SQR(x) (1LL * (x) * (x))
#define MASK(i) (1LL << (i))
#define Point Vector
#define left Left
#define right Right
#define div Div
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ld;
typedef pair<db, db> pdb;
typedef pair<ld, ld> pld;
typedef pair<int, int> pii;
typedef pair<int, pii> piii;
typedef pair<ll, ll> pll;
typedef pair<ll, pll> plll;
typedef pair<ll, int> pli;
typedef pair<ll, pii> plii;
template<class A, class B>
bool maximize(A& x, B y) {
if (x < y) return x = y, true; else return false;
}
template<class A, class B>
bool minimize(A& x, B y) {
if (x > y) return x = y, true; else return false;
}
/* END OF TEMPLATE */
const int N = 3e5 + 7;
int n, k;
vector<pii> seg;
ll res = 0;
namespace sub1 {
ll pre[N], suf[N];
ll pre_cnt[N], suf_cnt[N];
vector<int> E;
int idx(int x) {
return lower_bound(all(E), x) - E.begin() + 1;
}
void buildE() {
set<int> s;
for (auto x : seg) {
s.insert(x.X);
s.insert(x.Y);
}
E = vector<int>(s.begin(), s.end());
}
void Process() {
buildE();
int m = (int)E.size();
ll ANS = 9e18;
pre[0] = suf[n + 1] = 0;
pre_cnt[0] = suf_cnt[n + 1] = 0;
for (auto x : seg) {
pre[idx(x.Y)]+=x.Y;
pre_cnt[idx(x.Y)]++;
suf[idx(x.X)]+=x.X;
suf_cnt[idx(x.X)]++;
}
FOR(i, 1, m) {
pre[i]+=pre[i - 1];
pre_cnt[i]+=pre_cnt[i - 1];
}
FORD(i, m, 1) {
suf[i]+=suf[i + 1];
suf_cnt[i]+=suf_cnt[i + 1];
}
FOR(i, 1, m) {
int x = E[i - 1];
ll ans = 2LL * (pre_cnt[i - 1] * x - pre[i - 1]);
ans+=2LL * (suf[i + 1] - suf_cnt[i + 1] * x);
minimize(ANS, res + ans);
}
cout<<ANS;
}
}
namespace sub2 {
ll pre[N], suf[N];
vector<int> E;
int idx(int x) {
return lower_bound(all(E), x) - E.begin() + 1;
}
void buildE() {
set<int> s;
for (auto x : seg) {
s.insert(x.X);
s.insert(x.Y);
}
E = vector<int>(s.begin(), s.end());
}
ll pre_res[N], suf_res[N];
ll tmp[N];
void Process() {
buildE();
int m = (int)E.size();
ll ANS = 9e18;
sort(all(seg));
set<int> point;
for (auto x : seg) {
point.insert(x.X);
point.insert(x.Y);
}
FOR(i, 0, (int)point.size()) pre_res[i] = suf_res[i] = 1e18;
for (auto x : point) {
ll cost = 0;
REP(i, 0, (int)seg.size()) {
if (seg[i].Y < x) cost+=2LL * (x - seg[i].Y); else
if (seg[i].X > x) cost+=2LL * (seg[i].X - x);
minimize(pre_res[i], cost);
}
cost = 0;
FORD(i, (int)seg.size() - 1, 0) {
if (seg[i].Y < x) cost+=2LL * (x - seg[i].Y); else
if (seg[i].X > x) cost+=2LL * (seg[i].X - x);
minimize(suf_res[i], cost);
}
}
minimize(ANS, suf_res[0] + res);
minimize(ANS, pre_res[(int)point.size() - 1] + res);
REP(i, 0, (int)point.size() - 1) minimize(ANS, pre_res[i] + suf_res[i + 1] + res);
cout<<ANS;
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin>>k>>n;
FOR(i, 1, n) {
char P, Q;
int A, B;
cin>>P>>A>>Q>>B;
res+=abs(A - B);
if (P != Q) seg.push_back({min(A, B), max(A, B)}), res++;
}
if (seg.empty()) return cout<<res, 0;
if (k == 1) {
sub1::Process();
return 0;
}
if (k == 2) {
sub2::Process();
return 0;
}
return 0;
}
