#include <bits/stdc++.h>
#define FOR(i,j,k) for(int i=j; i<=k; ++i)
#define ROF(i,j,k) for(int i=j; i>=k; --i)
inline int read (void) {
int x = 0, f = 1, ch = getchar();
while(!isdigit(ch)) { if(ch == '-') f = -f; ch = getchar(); }
while(isdigit(ch)) { x = x * 10 + ch - '0'; ch = getchar(); }
return x * f;
}
using ll = long long;
using pii = std::pair <int, int>;
const int maxn = 100005;
inline bool cmp (pii p, pii q) {
return p.first + p.second < q.first + q.second;
}
char chp[5], chq[5];
pii p[maxn];
int a[maxn<<1];
ll pre[maxn], suf[maxn];
struct Node1 {
ll tot; std::priority_queue <int> q;
inline int top (void) { return q.top(); }
inline void push (int v) { tot += v; q.push(v); }
inline void pop (void) { tot -= q.top(); q.pop(); }
inline void clear (void) { tot = 0; while(!q.empty()) q.pop(); }
} q1;
struct Node2 {
ll tot; std::priority_queue <int, std::vector <int>, std::greater <int> > q;
inline int top (void) { return q.top(); }
inline void push (int v) { tot += v; q.push(v); }
inline void pop (void) { tot -= q.top(); q.pop(); }
inline void clear (void) { tot = 0; while(!q.empty()) q.pop(); }
} q2;
int main (void) {
int k = read(), N = read(), n = 0;
ll ans = 0;
FOR(i,1,N) {
scanf("%s", chp+1);
int s = read();
scanf("%s", chq+1);
int t = read();
if(s > t) std::swap (s, t);
if(chp[1] == chq[1])
ans += t - s;
else {
++ ans;
p[++ n] = {s, t};
}
}
if(k == 1) {
FOR(i,1,n) a[i*2-1] = p[i].first, a[i*2] = p[i].second;
std::sort(a+1, a+n*2+1);
FOR(i,1,n) ans -= a[i];
FOR(i,n+1,n*2) ans += a[i];
} else {
std::sort(p+1, p+n+1, cmp);
ll mn = 1ll << 60;
FOR(i,1,n) {
q1.push(p[i].first);
q2.push(p[i].second);
while(q1.top() > q2.top()) {
q2.push(q1.top()); q1.pop();
q1.push(q2.top()); q2.pop();
}
pre[i] = q2.tot - q1.tot;
}
q1.clear (); q2.clear ();
ROF(i,n,1) {
q1.push(p[i].first);
q2.push(p[i].second);
while(q1.top() > q2.top()) {
q2.push(q1.top()); q1.pop();
q1.push(q2.top()); q2.pop();
}
suf[i] = q2.tot - q1.tot;
}
FOR(i,0,n) mn = std::min(mn, pre[i] + suf[i+1]);
ans += mn;
}
printf("%lld\n", ans);
return 0;
}
