Uses crt;
var a,b,c:integer;
begin
read(a);
read(b);
read(c);
if ((a+b)>c) and ((a+c)>b) and ((b+c)>a) then
begin
if ((a=b) and (b<>c)) or ((a=c) and (c<>b)) or ((b=c) and (c<>a)) then writeln('Triangle is isosceles');
if (a=b) and (b=c) and (a=c) then writeln('Triangle is equilateral');
if (a<>b) and (a<>c) and (b<>c) then writeln ('Triangle is scalene');
end
else writeln('Triangle is invalid');
end.