#include
      
       #include
       
        #include
        
         using namespace std;int main(){    int n,m,i,j,w[10000+5];    double k[10000+5],dp[10000+5];    while(~scanf("%d%d",&n,&m))    {        if(n==0&&m==0) break;        for(i=0;i
         
          =w[i];j--)            {                dp[j]=min(dp[j],dp[j-w[i]]*k[i]);            }        }        dp[n]=1-dp[n];        dp[n]=dp[n]*100;        printf("%.1f%%\n",dp[n]);    }    return 0;}