var a,b:real;
begin
readln(a,b);
writeln('ploshad - ',a*b);
end.
var v,v0,t:real;
readln(v,v0,t);
writeln((v-v0)/t);
var a,b:real;
begin
readln(a,b);
writeln('ploshad - ',a*b);
end.
var v,v0,t:real;
begin
readln(v,v0,t);
writeln((v-v0)/t);
end.