#include <bits/stdc++.h>
using namespace std;
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define all(v) v.begin(), v.end()
#define sz(v) (int)v.size()
#define MOO(i, a, b) for(int i=a; i<b; i++)
#define M00(i, a) for(int i=0; i<a; i++)
#define MOOd(i,a,b) for(int i = (b)-1; i >= a; i--)
#define M00d(i,a) for(int i = (a)-1; i>=0; i--)
#define FAST ios::sync_with_stdio(0); cin.tie(0);
#define finish(x) return cout << x << '\n', 0;
#define dbg(x) cerr << ">>> " << #x << " = " << x << "\n";
#define _ << " _ " <<
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef pair<int,int> pi;
typedef pair<ld,ld> pd;
typedef complex<ld> cd;
const int MAX_N = 100100;
int k, n;
vector<pi> arr;
map<int,int> startsAt;
map<int,int> endsAt;
vi points;
ll getMinDis1() {
ll cur = 0;
ll numBefore = 0;
ll numAfter = 0;
for(pi p: arr) if(p.f > points[0]) {
numAfter++;
cur += p.f - points[0];
}
ll ans = cur;
MOO(i, 1, sz(points)) {
cur -= numAfter*(points[i] - points[i-1]);
numAfter -= startsAt[points[i]];
numBefore += endsAt[points[i-1]];
cur += numBefore*(points[i] - points[i-1]);
ans = min(ans, cur);
}
return ans;
}
vector<ll> getVals(vector<pi>& v) {
ll val = 0;
ll startAfter = 0;
ll endBefore = 0;
set<pi> stuff; // (x,0) = start at x, (x,1) = end at x
stuff.insert(mp(v[0].f ,0)); stuff.insert(mp(v[0].s, 1));
vector<ll> res; res.pb(0);
res.pb(val);
auto it = stuff.begin();
MOO(i, 1, sz(v)) {
stuff.insert(mp(v[i].f, 0));
if(v[i].f > (*it).f) {
val += v[i].f - (*it).f;
startAfter++;
}
stuff.insert(mp(v[i].s, 1));
if(v[i].s < (*it).f) {
val += (*it).f - v[i].s;
endBefore++;
}
while(startAfter > endBefore) {
if(next(it) == stuff.end()) break;
int curx = (*it).f;
int nextx = (*(next(it))).f;
val -= startAfter*(nextx - curx);
if((*it).s == 1) endBefore++;
it++;
if((*it).s == 0) startAfter--;
val += endBefore*(nextx - curx);
}
while(startAfter < endBefore) {
if(it == stuff.begin()) break;
int curx = (*it).f;
int nextx = (*(prev(it))).f;
val -= endBefore*(curx - nextx);
if((*it).s == 0) startAfter++;
it--;
if((*it).s == 1) endBefore--;
val += startAfter*(curx - nextx);
}
res.pb(val);
}
return res;
}
ll getMinDis2() {
vector<pair<int, pi>> tmp;
M00(i, sz(arr)) {
tmp.pb(mp(arr[i].f + arr[i].s, arr[i]));
}
sort(all(tmp));
vector<pi> sorted;
M00(i, sz(tmp)) sorted.pb(tmp[i].s);
M00(i, sz(sorted)) {
dbg(sorted[i].f _ sorted[i].s);
}
vector<ll> v1 = getVals(sorted);
reverse(all(sorted));
vector<ll> v2 = getVals(sorted);
reverse(all(v2));
M00(i, sz(v1)) {
dbg(i _ v1[i] _ v2[i]);
}
ll ans = 1e18;
M00(i, sz(v1)) {
ans = min(ans, v1[i]+v2[sz(v2)-1-i]);
}
return ans;
}
int main() { FAST
cin >> k >> n;
int cnt = 0;
ll ans = 0;
M00(i, n) {
string s1, s2;
int i1, i2;
cin >> s1 >> i1 >> s2 >> i2;
if(i1 > i2) swap(i1, i2);
if(s1 == s2) {
ans += (i2-i1);
} else {
cnt++;
ans += (i2-i1);
arr.pb(mp(i1,i2));
startsAt[i1]++;
endsAt[i2]++;
points.pb(i1);
points.pb(i2);
}
}
sort(all(points));
points.erase(unique(all(points)), points.end());
if(k == 1) {
ans += getMinDis1()*2LL + cnt;
} else {
ans += getMinDis2()*2LL + cnt;
}
finish(ans);
}
