#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template <class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define int long long int
#define endl '\n'
#define pb push_back
#define pi pair<int, int>
#define pii pair<int, pi>
#define fir first
#define sec second
#define MAXN 200005
#define mod 998244353
struct segtree
{
int n;
vector<int> seg;
int neutral()
{
return 0;
}
int merge(int a, int b)
{
return a + b;
}
segtree() {}
segtree(int sz)
{
n = 1;
while (n < sz)
n <<= 1;
seg.assign(n << 1, neutral());
}
void upd(int i, int value)
{
seg[i += n] += value;
for (i >>= 1; i; i >>= 1)
seg[i] = merge(seg[i << 1], seg[(i << 1) | 1]);
}
int qry(int l, int r)
{
int ansl = neutral(), ansr = neutral();
for (l += n, r += n + 1; l < r; l >>= 1, r >>= 1)
{
if (l & 1)
ansl = merge(ansl, seg[l++]);
if (r & 1)
ansr = merge(seg[--r], ansr);
}
return merge(ansl, ansr);
}
};
struct crazy_median
{
int n;
segtree st, st2;
ordered_set<pi> s;
map<int, int> mp;
vector<int> vals;
crazy_median(vector<int> v)
{
sort(v.begin(), v.end());
v.erase(unique(v.begin(), v.end()), v.end());
vals = v;
n = vals.size();
st = segtree(n);
st2 = segtree(n);
}
void add(int i)
{
int pos = lower_bound(vals.begin(), vals.end(), i) - vals.begin();
st.upd(pos, 1);
st2.upd(pos, i);
s.insert({i, mp[i]});
mp[i]++;
}
void rem(int i)
{
int pos = lower_bound(vals.begin(), vals.end(), i) - vals.begin();
st.upd(pos, -1);
st2.upd(pos, -i);
mp[i]--;
s.erase({i, mp[i]});
}
int calc(int x)
{
int ans = 0;
int pos = lower_bound(vals.begin(), vals.end(), x) - vals.begin();
ans += (st.qry(0, pos - 1) * x) - st2.qry(0, pos - 1);
ans += st2.qry(pos + 1, n - 1) - (st.qry(pos + 1, n - 1) * x);
return ans;
}
int solve()
{
int sz = s.size();
int x = (*s.find_by_order(sz / 2)).fir;
int ans = calc(x);
return ans;
}
};
void solve1(int n, int k)
{
int ans = 0;
vector<int> pts;
for (int i = 0; i < n; i++)
{
char c1, c2;
int a, b;
cin >> c1 >> a >> c2 >> b;
if (c1 == c2)
{
ans += abs(a - b);
}
else
{
ans++;
pts.pb(a);
pts.pb(b);
}
}
if (!pts.size())
{
cout << ans << endl;
return;
}
crazy_median cm(pts);
for (auto const &i : pts)
cm.add(i);
ans += cm.solve();
cout << ans << endl;
}
void solve2(int n, int k)
{
vector<pi> aux;
vector<pi> v;
int ans = 0;
for (int i = 0; i < n; i++)
{
char c1, c2;
int a, b;
cin >> c1 >> a >> c2 >> b;
v.pb({a, b});
if (c1 == c2)
{
ans += abs(a - b);
}
else
{
ans++;
aux.pb({a + b, i});
}
}
if (!aux.size())
{
cout << ans << endl;
return;
}
sort(aux.begin(), aux.end());
vector<int> pts;
for (auto const &i : aux)
{
pts.pb(v[i.sec].fir);
pts.pb(v[i.sec].sec);
}
crazy_median cm(pts), cm2(pts);
for (auto const &i : pts)
{
cm.add(i);
}
int need = ans;
vector<int> pts2;
ans += cm.solve();
while (pts.size() > 2)
{
cm.rem(pts.back());
cm2.add(pts.back());
pts.pop_back();
cm.rem(pts.back());
cm2.add(pts.back());
pts.pop_back();
int curr = need + cm.solve() + cm2.solve();
ans = min(ans, curr);
}
cout << ans << endl;
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n, k;
cin >> k >> n;
if (k == 1)
solve1(n, k);
else
solve2(n, k);
return 0;
}
