class z{static{try{for(;;){int x=0,y=0,z=0,t=48;for(;;){z=System.in.read()-t;if(z>-1)x=x*10+z;else if(z<-t)throw new Exception();else break;}for(;;){z=System.in.read()-t;if(z>-1)y=y*10+z;else break;}for(z=0;x*y>0;x--,y--)z+=x*y;System.out.println(z);}}catch(Exception e){}}}
Note that non-ascii characters in the above source code will be escaped (such as \x9f).