1 #include <cstdio> 2 #include <cstring> 3 #include <algorithm> 4 using namespace std; 5  6 int a[20000]; 7 double b[20000],dp[20000]; 8 int n,m; 9 10 int main()11 {12     while(scanf("%d%d",&n,&m)!=EOF)13     {14         memset(dp,0,sizeof(dp));15         if(n==0&&m==0) break;16         for(int i=1; i<=m; i++)17         {18             scanf("%d%lf",&a[i],&b[i]);19             b[i]=1-b[i];20         }21         for(int i=0; i<=n; i++)22         {23             dp[i]=1;24         }25         for(int i=1; i<=m; i++)26         {27             for(int j=n; j>=a[i]; j--)28             {29                 dp[j]=min(dp[j],dp[j-a[i]]*b[i]);30             }31         }32         printf("%.1lf%%\n",(1-dp[n])*100);33     }34     return 0;35 }