#include "bits/stdc++.h"
using namespace std;
const int maxn = 200005;
using ll = long long;
struct DS {
multiset<int> P, Q;
ll sumP, sumQ;
DS(){
sumP = sumQ = 0;
}
void add(int x){
if(P.empty()){
P.insert(x);
sumP += x;
}else if(*P.rbegin() < x){
Q.insert(x);
sumQ += x;
}else {
P.insert(x);
sumP += x;
}
if(P.size() < Q.size()){
sumP += *Q.begin();
sumQ -= *Q.begin();
P.insert(*Q.begin());
Q.erase(Q.begin());
}
if(P.size() > Q.size() + 1){
sumP -= *P.rbegin();
sumQ += *P.rbegin();
Q.insert(*P.rbegin());
P.erase(P.find(*P.rbegin()));
}
}
ll get(){
ll mid = *P.rbegin();
ll ans = sumQ - sumP;
ans -= mid * Q.size();
ans += mid * P.size();
return ans;
}
};
int main(int argc, char const *argv[])
{
ios::sync_with_stdio(false);
cin.tie(0);
int k, n;
cin >> k >> n;
vector<pair<ll, ll>> v;
ll ans = 0;
for(int i = 0; i < n; ++i){
char c, c1;
ll x, y;
cin >> c >> x >> c1 >> y;
if(c == c1){
ans += llabs(x - y);
}else {
++ans;
if(x > y)swap(x, y);
v.push_back({x, y});
}
}
if(v.empty()){
cout << ans << endl;
return 0;
}
n = v.size();
sort(v.begin(), v.end(), [&](pair<ll, ll> x, pair<ll, ll> y){
return x.first + x.second < y.first + y.second;
});
DS S, T;
vector<ll> pref(n + 1), suff(n + 1);
for(int i = 0; i < n; ++i){
S.add(v[i].first);
S.add(v[i].second);
pref[i] = S.get();
}
for(int i = n - 1; i >= 0; --i){
T.add(v[i].first);
T.add(v[i].second);
suff[i] = T.get();
}
ll res = 1e18;
for(int i = 0; i < n; ++i){
res = min(res, pref[i] + suff[i + 1]);
}
if(k == 1){
printf("%lld\n", pref[n - 1] + ans);
}else {
printf("%lld\n", ans + res);
}
return 0;
}
