//In the name of Allah
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define endl '\n'
#define F first
#define S second
#define pb push_back
#define all(x) x.begin(), x.end()
#pragma GCC optimize("O2")
const int N = 1e5 + 5;
int n, k, med[N][2], med2[N][2], p, q;
char ch1, ch2;
ll base, ans1[N], ans2[N];
vector<pair<ll, pair<int, int> > > ve;
priority_queue<int> q1, q3;
priority_queue<int, vector<int>, greater<int> > q2, q4;
int main()
{
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
ve.reserve(N);
cin >> k >> n;
for(int i = 0; i < n; i++)
{
cin >> ch1 >> p >> ch2 >> q;
//scanf("%c%d%c%d", &ch1, &p, &ch2, &q);
if(ch1 != ch2)
ve.pb({p + q, {min(p, q), max(p, q)}});
else
base += abs(p - q);
}
base += ve.size();
sort(all(ve));
ll s1 = 0, s2 = 0;
for(int i = 0; i < ve.size(); i++)
{
auto x = ve[i];
q1.push(x.S.F);
s1 += x.S.F;
q2.push(x.S.S);
s2 += x.S.S;
while(q1.top() > q2.top())
{
ll to1 = q1.top(), to2 = q2.top();
q1.pop();q2.pop();
q1.push(to2);
s1 -= to1, s1 += to2;
q2.push(to1);
s2 -= to2, s2 += to1;
}
ans1[i] = q1.top() * q1.size() - s1 + s2 - q1.top() * q2.size();
med[i][0] = q1.top();
med[i][1] = q2.top();
}
//cout << med[ve.size() - 1][0] << " " << med[ve.size() - 1][1] << endl;
//if(!n)
//cout << base << endl;
if(!ve.size())
{
cout << base << endl;
return 0;
}
if(k == 1|| ve.size() == 1)
{
ll ans1, ans2;
ans1 = ans2 = 0;
for(int i = 0; i < ve.size(); i++)
{
ans1 += abs(ve[i].S.F - med[ve.size() - 1][0]);
ans1 += abs(ve[i].S.S - med[ve.size() - 1][0]);
ans2 += abs(ve[i].S.F - med[ve.size() - 1][1]);
ans2 += abs(ve[i].S.S - med[ve.size() - 1][1]);
}
cout << min(ans1, ans2) + base << endl;
}
else
{
//cout << "BOOOM\n";
ll ans = 1e15 + 5;
ll s3 = 0, s4 = 0;
for(int i = ve.size() - 1; i >= 0; i--)
{
auto x = ve[i];
q3.push(x.S.F);
s3 += x.S.F;
q4.push(x.S.S);
s4 += x.S.S;
while(q3.top() > q4.top())
{
ll to1 = q3.top(), to2 = q4.top();
q3.pop();q4.pop();
q3.push(to2);
s3 -= to1, s3 += to2;
q4.push(to1);
s4 -= to2, s4 += to1;
}
//cout << q3.top() * q3.size() << " " << s3 << '\n';
ans2[i] = q3.top() * q3.size() - s3 + s4 - q3.top() * q4.size();
//if(ans2[i] == 0)
// cout << q3.top() << " " << q3.size() << " " << s3 << " " << s4 << " " << q4.top() << " " << q4.size() << '\n';
//med2[i][0] = q3.top();
//med2[i][1] = q4.top();
if(i == 0)
ans = min(ans, ans2[i]);
else
{
//cout << ans << " ";
ans = min(ans, ans2[i] + ans1[i - 1]);
//cout << ans << " " << ans2[i] + ans1[i - 1] << '\n';
//cout << i << " " << ans2[i] << " " << ans1[i - 1] << '\n';
}
}
ans = min(ans, ans1[ve.size() - 1]);
/*for(int i = 0; i < ve.size() - 1; i++)
{
ll ans1, ans2, ans3, ans4;
ans1 = ans2 = ans3 = ans4 = 0;
for(int j = 0; j <= i; j++)
{
ans1 += abs(ve[j].S.F - med[i][0]);
ans1 += abs(ve[j].S.S - med[i][0]);
ans2 += abs(ve[j].S.F - med[i][1]);
ans2 += abs(ve[j].S.S - med[i][1]);
}
for(int j = i + 1; j < ve.size(); j++)
{
ans3 += abs(ve[j].S.F - med2[i + 1][0]);
ans3 += abs(ve[j].S.S - med2[i + 1][0]);
ans4 += abs(ve[j].S.F - med2[i + 1][1]);
ans4 += abs(ve[j].S.S - med2[i + 1][1]);
}
ans = min(ans, min(ans1, ans2) + min(ans3, ans4));
}
ll ans1, ans2;
ans1 = ans2 = 0;
for(int i = 0; i < ve.size(); i++)
{
ans1 += abs(ve[i].S.F - med[ve.size() - 1][0]);
ans1 += abs(ve[i].S.S - med[ve.size() - 1][0]);
ans2 += abs(ve[i].S.F - med[ve.size() - 1][1]);
ans2 += abs(ve[i].S.S - med[ve.size() - 1][1]);
}
ans = min(ans, min(ans1, ans2));*/
//cout << base << '\n';
//cout << ans << '\n';
cout << ans + base << endl;
}
}
/*
2 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
*/
