题目1152：点菜问题

import java.io.IOException;
import java.io.FileReader;
import java.io.InputStreamReader;
import java.util.Scanner;
import java.util.Arrays;

class Main
{
	public static final boolean DEBUG = false;
	
	public static void main(String[] args) throws IOException
	{
		Scanner cin;
		int c, n;
		
		if (DEBUG) {
			cin = new Scanner(new FileReader("d:\\OJ\\uva_in.txt"));
		} else {
			cin = new Scanner(new InputStreamReader(System.in));
		}
		
		while (cin.hasNext()) {
			c = cin.nextInt();
			n = cin.nextInt();
			
			int price, value;
			int[] f = new int[c + 1];
			
			for (int i = 0; i < n; i++) {
				price = cin.nextInt();
				value = cin.nextInt();
				
				for (int j = c; j >= 0; j--) {
					if (j - price >= 0) {
						f[j] = Math.max(f[j], f[j - price] + value);
					}
				}
			}
			
			System.out.println(f[c]);
		}
	}
}