#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

int main() {
	int n, q, r[314160], c[314160], mc, mr, b, d;
	char s[10];
	memset(r, 0, sizeof(r));
	memset(c, 0, sizeof(c));
	mc=-1;
	mr=-1;
	scanf("%d%d", &n, &q);
	for(int i=0; i<q; i++) {
		scanf("%s%d%d", s, &b, &d); 
		if(s[0]=='R') c[b-1]+=d;
		else r[b-1]+=d;
	}
	for(int i=0; i<n; i++) if(r[i]>mr) mr=r[i];
	for(int i=0; i<n; i++) if(c[i]>mc) mc=c[i];
	printf("%d\n", mc+mr);
	return 0;
}