#include <bits/stdc++.h>
#define ll long long
using namespace std;
#ifdef BALBIT
#define bug(...) cerr<<"#"<<__LINE__<<": "<<#__VA_ARGS__<<" - ", _do(__VA_ARGS__)
template<typename T> void _do(T && x){cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T && x, S&&...y){cerr<<x<<", "; _do(y...);}
#define IOS()
#else
#define bug(...)
#define IOS() ios::sync_with_stdio(0), cin.tie(0)
#define endl '\n'
#endif // BALBIT
#define pii pair<ll, ll>
#define f first
#define s second
#define ALL(x) x.begin(), x.end()
#define SZ(x) (int)(x.size())
#define pb push_back
vector<pii> v;
int n;
ll C(ll l, ll r) {
if (l>r) swap(l,r);
ll re = 0;
for (pii & p : v) {
if (p.s < l) re += l-p.s;
else if (p.f > r) re += p.f-r;
else if (p.f>l && p.s < r) re += min (p.f-l, r-p.s);
}
return re;
}
ll RE;
vector<int> p;
int m;
void go(int il, int ir, int jl, int jr) {
if (il > ir || jl > jr) return;
int mid = (il + ir)/2;
int best = -1;
ll bestval = 2e18+3;
for (int j = jl; j<=jr; ++j) {
ll tt = C(mid, j);
RE = min (RE, tt);
if (tt < bestval) {
best = j; bestval = tt;
}
}
go(il, mid-1, jl, best);
go(mid+1, ir, best, jr);
}
signed main(){
IOS();
int k; cin>>k>>n;
ll re = 0;
map<int, int> hv;
for (int i = 0; i<n; ++i) {
char x, x2;
int l, r; cin>>x>>l>>x2>>r;
re += abs(r-l);
if (x == x2) {
}else{
if (r < l) swap(l,r);
v.pb({l,r});
hv[l]--;
hv[r]--;
}
}
n = SZ(v);
if (k == 1) {
ll now = C(0,0);
bug(now);
ll ans = now;
ll x = 0;
ll frt = n;
for (pii ele : hv) {
ll X = ele.f;
now -= (X-x) * (frt);
bug(X, now);
ans = min(ans, now);
frt += ele.s;
x=X;
}
cout<<re + ans*2 + n<<endl;
}else{
m = SZ(hv);
p.resize(m);
RE = C(0,0);
int _it = 0;
for (pii ele : hv) {
p[_it++] = ele.f;
}
go(0,m-1,0,m-1);
// cout<<re + ans*2 + n<<endl;
cout<<re + RE*2 + n<<endl;
}
}
/*
2 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
*/
