1 #include<iostream>
 2 #include<cstdio>
 3 using namespace std;
 4 double max(double a, double b)
 5 {
 6     if (a > b)
 7         return a;
 8     return b;
 9 }
10 int main()
11 {
12     int m, n, i, j, z[10005];
13     double dp[10005], d[10005];
14     while (scanf("%d%d",&n,&m)!=EOF,n+m)
15     {
16         for (i = 1;i <= m;i++)
17         {
18             cin >> z[i] >> d[i];
19             d[i] = d[i] * 100;
20         }
21         for (i = 0;i <= n;i++)
22             dp[i] = 0;
23         for (i = 1;i <= m;i++)
24             for (j = n;j >= z[i];j--)
25                 dp[j] = max(dp[j], dp[j - z[i]] + d[i] - dp[j - z[i]] * d[i]/100);
26         printf("%.1f%%\n", dp[n]);
27     }
28     return 0;
29 }