ll@n;
rep(n){
	ll@ti,@tf,@mi,@mf,@li,@lf;
	ll t=ti*100+tf,m=mi*100+mf,l=li*100+lf;
	ll v=bsearch_max[ll,v,0,510000](v*v*25<=(l*6480-v*t*18)*m);
	wtF("{v/100}.{v/10%10}{v%10}\n");
}