var a,c,b,sum,proz,raz:longint;
begin
read(a,b,c);
sum:=a+b+c;
proz:=a*b*c;
paz:=(a*a)-(b*b);
if (sum>proz)and(sum>razn) then writeln('summa');
if (proz>sum)and(proz>razn) then writeln('proizvedenie');
if (razn>sum)and(razn>proz) then writeln('raznost);
end.