1 //2017-05-24
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <iostream>
 5 #include <algorithm>
 6 
 7 using namespace std;
 8 
 9 const int N = 10010;
10 double dp[N];
11 
12 int main()
13 {
14     int n, m, C;
15     double W;
16     while(cin>>m>>n){
17         if(!n && !m)break;
18         for(int i = 0; i <= m; i++)dp[i] = 1.0;
19         for(int i = 1; i <= n; i++){
20             cin>>C>>W;
21             for(int j = m; j >= C; j--){
22                 dp[j] = min(dp[j], dp[j-C]*(1-W));
23             }
24         }
25         printf("%.1lf%%\n", (1-dp[m])*100);
26     }
27 
28     return 0;
29 }