백준 25304 JAVA

import java.io.*;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        int x = Integer.parseInt(br.readLine());
        int n = Integer.parseInt(br.readLine());


        int sum = 0;
        for (int i = 0; i < n; i++) {
            StringTokenizer st = new StringTokenizer(br.readLine(), " ");
            sum += Integer.parseInt(st.nextToken()) * Integer.parseInt(st.nextToken());
        }

        if (sum == x) {
            bw.write("Yes");
        } else {
            bw.write("No");
        }
        bw.flush();
    }
}