#include<stdio.h> #include<string.h> double min(double a,double b) { if(a<b)return a; return b; } int main() { int t,n,m,i,j,s,a[10001],k; double b[10001],f[10001]; while(scanf("%d%d",&n,&m),n||m) { for(j=0;j<=n;j++) f[j]=1.0; for(i=0;i<m;i++) scanf("%d%lf",&a[i],&b[i]); for(i=0;i<m;i++) for(j=n;j>=a[i];j--) f[j]=min(f[j],f[j-a[i]]*(1-b[i])); printf("%.1f%%\n",(1-f[n])*100); } return 0; }