void main(){ import std.stdio, std.string, std.conv, std.algorithm; import std.typecons, std.math; alias P=Tuple!(double, "x", double, "y", double, "z"); auto abc=new P[](3); foreach(i; 0..3) rd(abc[i].x, abc[i].y, abc[i].z); P d; rd(d.x, d.y, d.z); alias V=P; V vectorizeAtoB(P A, P B){ // from:A to:B return V(B.x-A.x, B.y-A.y, B.z-A.z); } double dot(V v1, V v2){ return v1.x*v2.x+v1.y*v2.y+v1.z*v2.z; } bool ok=true; foreach(i; 0..3){ auto vd=vectorizeAtoB(abc[i], d), v1=vectorizeAtoB(abc[i], abc[(i-1+3)%3]), v2=vectorizeAtoB(abc[i], abc[(i+1)%3]); if(dot(vd, v1)<0 || dot(vd, v2)<0) ok=false; } if(ok) writeln("Yes"); else writeln("No"); } void rd(T...)(ref T x){ import std.stdio, std.string, std.conv; auto l=readln.split; assert(l.length==x.length); foreach(i, ref e; x){ e=l[i].to!(typeof(e)); } } void wr(T...)(T x){ import std.stdio; foreach(e; x) write(e, " "); writeln(); }