#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(int i = 1; i <= n; ++i)
#define forn(i, l, r) for(int i = l; i <= r; ++i)
#define ford(i, r, l) for(int i = r; i >= l; --i)
#define FOR(i, n) for(int i = 0; i < n; ++i)
#define FORD(i, n) for(int i = n - 1; i >= 0; --i)
#define fi first
#define se second
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pb push_back
#define endl "\n"
#define task "bridges"
#define sz(a) int(a.size())
#define C(x, y) make_pair(x, y)
#define all(a) (a).begin(), (a).end()
#define bit(i, mask) (mask >> i & 1)
template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }
inline int readInt() {char c;while(c=getchar(),c!='-'&&(c<'0'||c>'9'));bool sign=(c=='-');if(sign)c=getchar();int n=c-'0';while(c=getchar(),c>='0'&&c<='9')n=10*n+c-'0';return(!sign)?n:-n;}
inline ll readLong() {char c;while(c=getchar(),c!='-'&&(c<'0'||c>'9'));bool sign=(c=='-');if(sign)c=getchar();ll n=c-'0';while(c=getchar(),c>='0'&&c<='9')n=10*n+c-'0';return(!sign)?n:-n;}
inline string readString() {char c;while(c=getchar(),c==' '||c=='\n'||c=='\t');string s({c});while(c=getchar(),c!=EOF&&c!=' '&&c!='\n'&&c!='\t')s+=c;return s;}
const int N = 2e5 + 10;
const int M = 1e3 + 3;
const int N1 = 2e3 + 10;
const int K = 1e2 + 1;
const int MOD = 1e9 + 7;
const int INF = 0x3f3f3f3f;
const ll LINF = 1e17 + 2;
const int block_size = 500;
const int LOG = 29;
const int offset = N;
const int LIM = 11 ;
const int AL = 26;
int k, n;
struct Med
{
priority_queue<int> l;
priority_queue<int, vector<int>, greater<int>> r;
ll l_sum = 0, r_sum = 0;
void init()
{
l_sum = r_sum = 0;
while(sz(l)) l.pop(); while(sz(r)) r.pop();
}
void add(int x)
{
l.push(x);
l_sum += x;
x = l.top();
r.push(x);
r_sum += x;
l_sum -= x;
l.pop();
if(sz(l) < sz(r))
{
x = r.top();
r.pop(); r_sum -= x;
l.push(x); l_sum += x;
}
}
ll get() {return r_sum - l_sum;}
} med;
ll res = 0;
vector<pii> segments;
ll pref[N];
void solve()
{
cin >> k >> n;
rep(i, n)
{
char p, q;
int x, y;
cin >> p >> x >> q >> y;
if(x > y) swap(x, y);
if(p == q) res += y - x;
else
{
++res;
segments.pb({x, y});
}
}
sort(all(segments), [] (const pii &x, const pii &y){
return x.fi + x.se < y.fi + y.se;
});
rep(i, sz(segments))
{
med.add(segments[i - 1].fi);
med.add(segments[i - 1].se);
pref[i] = med.get();
}
med.init();
ll ans = res + pref[sz(segments)];
if(k == 2)
{
ford(i, sz(segments), 1)
{
med.add(segments[i - 1].fi);
med.add(segments[i - 1].se);
minimize(ans, res + pref[i - 1] + med.get());
}
}
cout << ans << endl;
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int TC = 1;
if(fopen(task".inp", "r"))
{
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
while(TC--)
{
solve();
cout << endl;
}
return 0;
}
