#include<bits/stdc++.h>
using namespace std;
int dp[101][101];
int w[101],c[101];
int main(){
   int n,m;
   cin>>m>>n;
   for(int i = 1;i<=n;i++){
   	cin>>w[i]>>c[i];
   }
   for(int i = 1;i<=n;i++){
   	for(int j = 1;j<=m;j++){
   		if(j<w[i]){
   			dp[i][j] = dp[i-1][j];
      }else{
   dp[i][j] = max(dp[i-1][j-w[i]]+c[i],dp[i-1][j]);
   	}
   }
}
   cout<<dp[n][m];
   return 0;
}

样例没问题啊，呜呜······