#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
using namespace std;
typedef long long LL;
typedef pair<int, int> pii;
typedef pair<LL, LL> pll;
LL temp, ans=987654321987654321;
int n, re, k;
LL arr[200010];
struct SEGMENT_TREE {
struct NODE {
int st, fin, len;
long long sum, maxx, minn;
long long lazy;
} tree[3000000];
const long long inf=987654321987654321;
int x;
void relaxnode(int point){
tree[point].maxx=max(tree[point*2].maxx+tree[point*2].lazy, tree[point*2+1].maxx+tree[point*2+1].lazy);
tree[point].minn=min(tree[point*2].minn+tree[point*2].lazy, tree[point*2+1].minn+tree[point*2+1].lazy);
tree[point].sum=tree[point*2].sum+tree[point*2].lazy*tree[point*2].len+tree[point*2+1].sum+tree[point*2+1].lazy*tree[point*2+1].len;
}
void maketree(int point, int num) {
if(num==1) {
x++;
tree[point].st=tree[point].fin=x;
tree[point].len=1;
}
if(num<=1)
return;
maketree(point*2, num-num/2);
maketree(point*2+1, num/2);
tree[point].st=tree[point*2].st;
tree[point].fin=tree[point*2+1].fin;
tree[point].len=tree[point*2].len+tree[point*2+1].len;
}
long long sumrange(int a, int b, int point) {
if(tree[point].st==tree[point].fin) {
tree[point].maxx+=tree[point].lazy;
tree[point].minn+=tree[point].lazy;
tree[point].sum+=tree[point].lazy*tree[point].len;
tree[point].lazy=0;
}
if(tree[point].st>=a&&tree[point].fin<=b)
return tree[point].sum+tree[point].lazy*tree[point].len;
if(tree[point].st>b||tree[point].fin<a)
return 0;
tree[point*2].lazy+=tree[point].lazy;
tree[point*2+1].lazy+=tree[point].lazy;
tree[point].lazy=0;
LL ret=sumrange(a, b, point*2)+sumrange(a, b, point*2+1);
relaxnode(point);
return ret;
}
long long maxrange(int a, int b, int point) {
if(tree[point].st==tree[point].fin) {
tree[point].maxx+=tree[point].lazy;
tree[point].minn+=tree[point].lazy;
tree[point].sum+=tree[point].lazy*tree[point].len;
tree[point].lazy=0;
}
if(tree[point].st>=a&&tree[point].fin<=b)
return tree[point].maxx+tree[point].lazy;
if(tree[point].st>b||tree[point].fin<a)
return -inf;
tree[point*2].lazy+=tree[point].lazy;
tree[point*2+1].lazy+=tree[point].lazy;
tree[point].lazy=0;
LL ret=max(maxrange(a, b, point*2), maxrange(a, b, point*2+1));
relaxnode(point);
return ret;
}
long long minrange(int a, int b, int point) {
if(tree[point].st==tree[point].fin) {
tree[point].maxx+=tree[point].lazy;
tree[point].minn+=tree[point].lazy;
tree[point].sum+=tree[point].lazy*tree[point].len;
tree[point].lazy=0;
}
if(tree[point].st>=a&&tree[point].fin<=b)
return tree[point].minn+tree[point].lazy;
if(tree[point].st>b||tree[point].fin<a)
return inf;
tree[point*2].lazy+=tree[point].lazy;
tree[point*2+1].lazy+=tree[point].lazy;
tree[point].lazy=0;
LL ret=min(minrange(a, b, point*2), minrange(a, b, point*2+1));
relaxnode(point);
return ret;
}
void updaterange(int point, int num, long long p) {
if(tree[point].st==tree[point].fin) {
tree[point].sum=tree[point].maxx=tree[point].minn=p;
tree[point].lazy=0;
return;
}
tree[point*2].lazy+=tree[point].lazy;
tree[point*2+1].lazy+=tree[point].lazy;
tree[point].lazy=0;
if(num<=tree[point*2].fin)
updaterange(point*2, num, p);
else
updaterange(point*2+1, num, p);
relaxnode(point);
}
void alterrange(int point, int a, int b, long long p) {
if(tree[point].fin<a||tree[point].st>b)
return;
if(tree[point].st>=a&&tree[point].fin<=b) {
if(tree[point].st==tree[point].fin) {
tree[point].maxx+=tree[point].lazy;
tree[point].minn+=tree[point].lazy;
tree[point].sum+=tree[point].lazy*tree[point].len;
tree[point].lazy=0;
}
tree[point].lazy+=p;
return;
}
tree[point*2].lazy+=tree[point].lazy;
tree[point*2+1].lazy+=tree[point].lazy;
tree[point].lazy=0;
alterrange(point*2, a, b, p);
alterrange(point*2+1, a, b, p);
relaxnode(point);
}
void init(int n) {
maketree(1, n);
}
long long get_sum(int a, int b) {
return sumrange(a, b, 1);
}
long long get_min(int a, int b) {
return minrange(a, b, 1);
}
long long get_max(int a, int b) {
return maxrange(a, b, 1);
}
void update(int a, long long num) {
updaterange(1, a, num);
}
void alter(int a, int b, long long num) {
alterrange(1, a, b, num);
}
}seg;
int main()
{
scanf("%d %d", &k, &n);
for(int i=1; i<=n; i++){
char a, b;
LL c, d;
scanf(" %c %lld %c %lld", &a, &c, &b, &d);
if(a==b)temp+=llabs(c-d);
else{
arr[++re]=c;
arr[++re]=d;
}
}
sort(arr+1, arr+re+1);
seg.init(re);
for(int i=1; i<=re; i++){
seg.update(i, arr[i]);
}
if(k==1){
ans=seg.get_sum(re/2+1, re);
ans-=seg.get_sum(1, re/2);
printf("%lld", ans+temp+(LL)re/2);
return 0;
}
}
