#include<bits/stdc++.h>
using namespace std;
#define ll long long
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
/*int k, n;
cin >> k >> n;
vector<pair<int, int>> a, p;
int res = 0;
for(int i = 0; i < n; i++) {
char c1, c2;
int a1, a2;
cin >> c1 >> a1 >> c2 >> a2;
if(c1 == c2) {
res += abs(a1-a2);
}
else {
a.push_back({a1, a2});
}
}
// incorrect when k = 2 couse need to choose
sort(a.begin(), a.end());
for(auto i: a) {
pair<int, int> cur = {i.first, i.second};
if(p.empty()) {
p.push_back(cur);
continue;
}
if(p.back().second >= cur.first) {
p.back() = {cur.first, p.back().second};
}
else {
p.push_back(cur);
}
}
int i = 0; // point to cur element in a
int j = 0; // point to element in p
int cross = 0;
while(k > 0 && j < p.size()) {
cross = p[j].second;
while(i < a.size() && a[i].first <= cross) {
res += abs(a[i].second-a[i].first);
i++;
}
j++;
k--;
}
while(i < a.size()) {
res += abs(a[i].second-a[i].first) + 2*abs(cross-a[i].first);
i++;
}
cout << res+a.size() << endl;*/
int k, n;
cin >> k >> n;
vector<int> a;
vector<pair<ll, ll>> p;
ll res = 0;
for(int i = 0; i < n; i++) {
char c1, c2;
ll a1, a2;
cin >> c1 >> a1 >> c2 >> a2;
if(c1 == c2) {
res += abs(a1-a2);
}
else {
a.push_back(a1);
a.push_back(a2);
p.push_back({a1, a2});
}
}
sort(a.begin(), a.end());
if(k == 1) {
int m = a.size()/2;
for(auto i: p) {
res += abs(a[m]-i.first) + abs(a[m]-i.second)+1;
}
}
else {
// dist from middle should be as small as possible
ll l = 0, r = 0;
for(int i = 0; i < n; i++) {
r += a[i];
}
ll cur = r;
for(int i = 0; i < n; i++) {
r -= a[i];
l += a[i];
cur = min(cur, r-l);
}
res += cur;
}
cout << res << "\n";
return 0;
}
