#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef tree<pair<long long,long long>,null_type,less<pair<long long,long long>>,rb_tree_tag,tree_order_statistics_node_update> oset;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define ll long long
#define all(x) (x).begin(), (x).end()
#define king ios::sync_with_stdio(false); cin.tie(nullptr);cout.tie(0)
int n, k, maxn;
oset st;
vector<ll> tr;
ll que(int i){ ll sm=0; for(; i>=1; i-=i&-i) sm += tr[i]; return sm; }
void up(int i,ll x){ for(; i<=maxn; i+=i&-i) tr[i] += x; }
map<ll,ll> pos;
ll ans = 0;
ll cal(){
if(st.size() < 2) return 0;
int idx = (int)(st.size()/2);
idx--;
auto xx = st.find_by_order((size_t)idx);
ll x = xx->first;
ll low = 0, hi = 0;
if(pos[x]-1 > 0) low = que(pos[x]-1);
hi = que(maxn) - que(pos[x]);
return (x*idx - low) + (hi - x*(idx+1));
}
vector<tuple<ll,ll,ll>> vec;
vector<ll> pf, suf;
int main(){
king;
cin >> k >> n;
maxn = 2 * n;
tr.assign(maxn + 3, 0);
vector<ll> com;
vector<ll> k1;
for(int i = 1; i <= n; ++i){
char q,w;
int x,y;
cin >> q >> x >> w >> y;
if(q == w){
ans += llabs((ll)x - (ll)y);
} else {
ans++; vec.push_back({(x + y) / 2, x, y});
if(k == 1){ k1.push_back(x); k1.push_back(y); }
}
com.push_back(x); com.push_back(y);
}
if(k == 1){
if(k1.empty()){
cout << ans;
return 0;
}
sort(all(k1));
size_t m = k1.size();
size_t mid = m/2;
if(mid == 0){
cout << ans;
return 0;
}
mid = mid - 1;
ll x = k1[mid];
ll low = 0, hi = 0;
for(size_t i = 0; i < mid; ++i) low += k1[i];
for(size_t i = mid+1; i < m; ++i) hi += k1[i];
cout << ans + (x * (ll)mid - low) + (hi - x * (ll)(mid + 1));
return 0;
}
sort(all(com));
com.erase(unique(all(com)), com.end());
for(size_t i = 0; i < com.size(); ++i) pos[com[i]] = (int)(i + 1);
sort(vec.begin(), vec.end(), [](const tuple<ll,ll,ll> &A, const tuple<ll,ll,ll> &B){
ll ax = min(get<1>(A), get<2>(A));
ll bx = min(get<1>(B), get<2>(B));
return ax < bx;
});
pf.assign(vec.size(), 0);
suf.assign(vec.size(), 0);
ll cnt = 0;
for(size_t i = 0; i < vec.size(); ++i){
auto [s,x,y] = vec[i];
st.insert({x, cnt++}); st.insert({y, cnt++});
up((int)pos[x], x); up((int)pos[y], y);
pf[i] = cal();
}
st.clear();
reverse(all(vec));
fill(tr.begin(), tr.end(), 0);
cnt = 0;
for(size_t i = 0; i < vec.size(); ++i){
auto [s,x,y] = vec[i];
st.insert({x, cnt++}); st.insert({y, cnt++});
up((int)pos[x], x); up((int)pos[y], y);
suf[(vec.size()-1) - i] = cal();
}
if(vec.empty()){
cout << ans;
return 0;
}
ll mn = (ll)4e18;
if(vec.size() == 1){
mn = min(pf[0], suf[0]);
} else {
for(size_t i = 0; i + 1 < vec.size(); ++i){
mn = min(mn, pf[i] + suf[i+1]);
}
}
cout << mn + ans;
return 0;
}
