#include "bits/stdc++.h"
using namespace std;
const int maxn = 200005;
using ll = long long;
map<ll, int> mp;
ll f[maxn];
struct DS {
vector<ll> v;
void add(ll x){
v.push_back(x);
}
ll get(){
sort(v.begin(), v.end());
int sz = v.size();
ll mid = f[v[sz / 2]];
ll ret = 0;
for(int i = 0; i < sz; ++i){
ret += llabs(f[v[i]] - mid);
}
return ret;
}
};
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});
mp[x];
mp[y];
}
}
if(v.empty()){
cout << ans << endl;
return 0;
}
int cnt = 0;
for(auto& i : mp){
i.second = ++cnt;
f[cnt] = i.first;
}
n = v.size();
for(int i = 0; i < n; ++i){
v[i].first = mp[v[i].first];
v[i].second = mp[v[i].second];
}
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]);
}
res = min(res, pref[n - 1]);
if(k == 1){
printf("%lld\n", pref[n - 1] + ans);
}else {
printf("%lld\n", ans + res);
}
return 0;
}
