#include <bits/stdc++.h>
using namespace std;
struct ff
{
	int t , v;
} a[1005];
int ans;
int dp[10005];
signed main ()
{
	int n , tim;
	scanf ("%d%d" , &tim , &n);
	for (register int i = 1; i <= n; i++) scanf ("%d%d" , &a[i].t , &a[i].v);


		{
			dp[j] = max (dp[j] , dp[j - a[i].t] + a[i].v);
		}
	}
	cout << dp[tim];
	return 0;
}

注意：

for (register int i = 1; i <= tim/*这里应该是n*/; i++)

这还能AC？