usaco 3.1 Score Inflation

/*
ID: modengd1
PROG: inflate
LANG: C++
*/
#include <iostream>
#include <stdio.h>
#include <memory.h>
int dp[10000];
int T[10000],w[10000];
int N,M;
using namespace std;

int main()
{
    freopen("inflate.in","r",stdin);
    freopen("inflate.out","w",stdout);
    scanf("%d%d",&M,&N);
    memset(dp,0,sizeof(dp));
    for(int i=0;i<N;i++)
    {
        scanf("%d%d",&w[i],&T[i]);
    }
    for(int i=0;i<N;i++)
    {
        for(int j=T[i];j<=M;j++)
        {
            dp[j]=max(dp[j-T[i]]+w[i],dp[j]);
        }
    }
    cout<<dp[M]<<endl;
    return 0;
}