#include <bits/stdc++.h>
#define FIXED_FLOAT(x) std::fixed <<std::setprecision(20) << (x)
#define all(v) (v).begin(), (v).end()
using namespace std;
#define forn(i,n) for (int i = 0; i < (n); ++i)
#define rforn(i, n) for(int i = (n) - 1;i >= 0;--i)
using ll = long long;
int mod = (ll)1e9 + 7;
#define PI acos(-1)
typedef pair<int, int> pairs;
const int INF = 1e9 + 1;
const int N = 2e5 + 100;
const double eps = 1e-7;
template <class T> using V = vector<T>;
template <class T> using VV = V<V<T>>;
template <typename XPAX>
void ckma(XPAX &x, XPAX y) {
x = (x < y ? y : x);
}
template <typename XPAX>
void ckmi(XPAX &x, XPAX y) {
x = (x > y ? y : x);
}
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
priority_queue<int> lf;
priority_queue<int, V<int>, greater<int>> rf;
ll lsum, rsum;
void ins(int x) {
int med = (lf.size() ? lf.top() : INF);
if(x <= med) {
lf.push(x);
lsum += x;
}
else {
rf.push(x);
rsum += x;
}
if(rf.size() + 1 < lf.size()) {
int ns = lf.top();
lf.pop();
lsum -= ns;
rsum += ns;
rf.push(ns);
}
if(lf.size() < rf.size()) {
int ns = rf.top();
rf.pop();
rsum -= ns;
lsum += ns;
lf.push(ns);
}
}
void solve() {
int n, k;
cin >> k >> n;
V<pairs> ps{{0, 0}};
auto cmp = [&](pairs a, pairs b) {
return a.first + a.second < b.first + b.second;
};
ll same = 0;
forn(i, n) {
char a, b;
int x, y;
cin >> a >> x >> b >> y;
if(a == b)same += abs(x - y);
else
ps.push_back({x, y});
}
sort(all(ps), cmp);
n = ps.size() - 1;
same += n;
V<ll> pr(n + 1, 0);
lsum = rsum = 0;
for(int i = 1;i <= n;++i) {
ins(ps[i].first);
ins(ps[i].second);
pr[i] = rsum - lsum;
}
ll ans = pr[n];
if(k == 2) {
while(lf.size())lf.pop();
while(rf.size())rf.pop();
lsum = rsum = 0;
for(int i = n;i;--i) {
ins(ps[i].first);
ins(ps[i].second);
ckmi(ans, pr[i - 1] + rsum - lsum);
}
}
cout << ans + same << '\n';
}
void test_case() {
int t;
cin >> t;
forn(p, t) {
//cout << "Case #" << p + 1 << ": ";
solve();
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
solve();
}
