#include<bits/stdc++.h>
using namespace std;
const int maxn=105,maxv=1005;
int n,allv,w[maxn],p[maxn],f[maxv];
int read(){
	int ret=0;char ch=getchar();
	while (ch<'0'||'9'<ch) ch=getchar();
	while ('0'<=ch&&ch<='9') ret=ret*10+ch-'0',ch=getchar();
	return ret;
}
int main(){
//	freopen("medic.in","r",stdin);
//	freopen("medic.out","w",stdout);
	allv=read(),n=read();
	for (int i=1;i<=n;i++) w[i]=read(),p[i]=read();
	for (int i=1;i<=n;i++)
	for (int j=allv;j>w[i];j--)
	  f[j]=max(f[j-w[i]]+p[i],f[j]);
	printf("%d\n",f[allv]);
	return 0;
}

是哪里错了