#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define ar array
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template <typename T> using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define vt vector
#define pb push_back
#define all(c) (c).begin(), (c).end()
#define sz(x) (int)(x).size()
#define pll pair<ll, ll>
#define pii pair<int, int>
#define pld pair<ld, ld>
#define f first
#define s second
#define F_OR(i, a, b, s) for (int i=(a); (s)>0?i<(b):i>(b); i+=(s))
#define F_OR1(e) F_OR(i, 0, e, 1)
#define F_OR2(i, e) F_OR(i, 0, e, 1)
#define F_OR3(i, b, e) F_OR(i, b, e, 1)
#define F_OR4(i, b, e, s) F_OR(i, b, e, s)
#define GET5(a, b, c, d, e, ...) e
#define F_ORC(...) GET5(__VA_ARGS__, F_OR4, F_OR3, F_OR2, F_OR1)
#define FOR(...) F_ORC(__VA_ARGS__)(__VA_ARGS__)
#define EACH(x, a) for (auto& x: a)
template<class T> bool umin(T& a, const T& b) {
return b<a?a=b, 1:0;
}
template<class T> bool umax(T& a, const T& b) {
return a<b?a=b, 1:0;
}
ll FIRSTTRUE(function<bool(ll)> f, ll lb, ll rb) {
while(lb<rb) {
ll mb=(lb+rb)/2;
f(mb)?rb=mb:lb=mb+1;
}
return lb;
}
ll LASTTRUE(function<bool(ll)> f, ll lb, ll rb) {
while(lb<rb) {
ll mb=(lb+rb+1)/2;
f(mb)?lb=mb:rb=mb-1;
}
return lb;
}
template<class A> void read(vt<A>& v);
template<class A, size_t S> void read(ar<A, S>& a);
template<class A, class B> void read(pair<A, B>& x);
template<class T> void read(T& x) {
cin >> x;
}
void read(double& d) {
string t;
read(t);
d=stod(t);
}
void read(long double& d) {
string t;
read(t);
d=stold(t);
}
template<class H, class... T> void read(H& h, T&... t) {
read(h);
read(t...);
}
template<class A> void read(vt<A>& x) {
EACH(a, x)
read(a);
}
template<class A, size_t S> void read(array<A, S>& x) {
EACH(a, x)
read(a);
}
template<class A, class B> void read(pair<A, B>& x) {
cin >> x.first >> x.second;
}
string to_string(char c) {
return string(1, c);
}
string to_string(bool b) {
return b?"true":"false";
}
string to_string(const char* s) {
return string(s);
}
string to_string(string s) {
return s;
}
string to_string(vt<bool> v) {
string res;
FOR(sz(v))
res+=char('0'+v[i]);
return res;
}
template<size_t S> string to_string(bitset<S> b) {
string res;
FOR(S)
res+=char('0'+b[i]);
return res;
}
template<class T> string to_string(T v) {
bool f=1;
string res;
EACH(x, v) {
if(!f)
res+=' ';
f=0;
res+=to_string(x);
}
return res;
}
template<class A, class B> string to_string(pair<A, B>& x) {
return to_string(x.first) + ' ' + to_string(x.second);
}
template<class A> void write(A x) {
cout << to_string(x);
}
template<class H, class... T> void write(const H& h, const T&... t) {
write(h);
write(t...);
}
void print() {
write("\n");
}
template<class H, class... T> void print(const H& h, const T&... t) {
write(h);
if(sizeof...(t))
write(' ');
print(t...);
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
int k, n; read(k, n);
char a, b; int c, d;
ll ans=0, cnt=0;
vt<int> v;
FOR(n) {
read(a, c, b, d);
if (a==b) {
ans+=abs(d-c);
} else {
cnt++;
v.pb(c), v.pb(d);
}
}
if (k==1) {
sort(all(v));
FOR(cnt) ans+=v[cnt-1]-v[i];
FOR(i, cnt, 2*cnt) ans+=v[i]-v[cnt-1];
print(ans+cnt);
} else {
ll a=LLONG_MAX;
int l=0, r=0;
vt<ll> pre(cnt+1); pre[0]=0;
FOR(cnt) pre[i+1]=pre[i]+v[i];
set<pii> b;
while (l<cnt) {
cout << "pre: " << l << " " << r << endl;
while (r+1<cnt) {
auto it=b.upper_bound(make_pair((v[r]+v[l])/2, cnt));
int idx=it!=b.begin() ? prev(it)->s : l;
cout << l << " " << idx << " " << r << endl;
if (umin(a, (l*v[l]-pre[l])+(pre[idx+1]-pre[l]-(idx-l+1)*v[l])+((r+1-idx)*v[r]-pre[r+2]+pre[idx])+((pre[n]-pre[r+1])-(n-r-2)*v[r+1]))) b.insert({v[r], r++});
else break;
}
auto it=b.upper_bound(make_pair((v[r]+v[l])/2, cnt));
int idx=it!=b.begin() ? prev(it)->s : l;
cout << "post: " << l << " " << r << endl;
umin(a, (l*v[l]-pre[l])+(pre[idx+1]-pre[l]-(idx-l+1)*v[l])+((r-idx)*v[r]-pre[r+1]+pre[idx])+((pre[n]-pre[r])-(n-r-1)*v[r]));
b.erase({v[l], l++});
}
print(ans+a+cnt);
}
}
