import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintStream;
import java.util.*;

public class a {
    public static void main(String[] args) throws FileNotFoundException {
        Scanner scn = new Scanner(new File("paint.in"));
        int N = scn.nextInt();
        int K = scn.nextInt();
        TreeMap<Integer,Integer> positions = new TreeMap<>();
        int curr_pos = 0;
        char dir = 'X';
        for(int i=0;i<N;i++){
            int dist = scn.nextInt();
            char new_dir = scn.next().charAt(0);
            if(new_dir == 'R') {
                positions.putIfAbsent(curr_pos, 0);
                positions.replace(curr_pos, positions.get(curr_pos) + 1);
                curr_pos += dist;
                positions.putIfAbsent(curr_pos, 0);
                positions.replace(curr_pos, positions.get(curr_pos) - 1);
            } else {
                curr_pos -= dist;
                positions.putIfAbsent(curr_pos, 0);
                positions.replace(curr_pos, positions.get(curr_pos) + 1);
                curr_pos += dist;
                positions.putIfAbsent(curr_pos, 0);
                positions.replace(curr_pos, positions.get(curr_pos) - 1);
                curr_pos -= dist;
            }
        }
        int ans = 0;
        int curr = 0;
        int prev = 0;
        for(int pos : positions.keySet()) {
            if(curr >= K) {
                ans += pos - prev;
            }
            curr += positions.get(pos);
            prev = pos;
        }
        PrintStream ps = new PrintStream("paint.out");
        ps.println(ans);
        ps.close();
    }
}