#include <bits/stdc++.h>
using namespace std;
int n,m,dp[31][201];
vector<pair<int,int> > thing;
int main(){
	scanf("%d%d",&m,&n);
	thing.push_back(make_pair(0,0));
	for(int i = 1;i<=n;i++){
		int a,b;
		scanf("%d%d",&a,&b);
		thing.push_back(make_pair(a,b));
	}
	for(int i = 1;i<=n;i++)
		for(int j = 1;j<=m;j++)
			if(j<thing[i].first)dp[i][j] = dp[i-1][j];
			else dp[i][j] = max(dp[i-1][j],dp[i][j-thing[i].first]+thing[i].second);
	printf("max=%d",dp[n][m]);
	return 0;
}