File standardInput readLine split map(asNumber)do(s:=at(0);e:=at(1);p:=last;for(i,0,p,c:=a:=(e-s)*i+s*p;d:=p;while(0<d=c%c=d,1);write(a/c,if(p/c>1,"/".. p/c,"")," ")))