#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <complex>
#include <cstdio>
#include <cstring>
#include <deque>
#include <iomanip>
#include <iterator>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <vector>
#include <iostream>
using namespace std;
#define int long long
#define all(x) begin(x), end(x)
#define sz(x) (int) (x).size()

const int mxn = 1e5;

int k,n;

//solve1 
void solve1() {
	vector<int> ep;
	int ans=0;
	for (int i=0; i<n; i++) {
		char a,b; int c,d;
		cin >> a >> c >> b >> d;
		if (a != b) {
			ep.push_back(c);
			ep.push_back(d);
			ans++;
		} else {
			ans += abs(c-d);
		}
	}
	sort(all(ep));
	int kp = ep[sz(ep)/2];
	for (int i : ep) {
		ans += abs(kp-i);
	}
	cout << ans << "\n";
}

signed main() {
	ios::sync_with_stdio(false); cin.tie(nullptr);
	
	cin>>k>>n;
	if (k==1) {
		solve1();
	}
	
	return 0;
}