var
x,y,t:integer;
vvod:char;
begin
readln(x,y);
readln(vvod)
if vvod='a' then x:=x-y
else if vvod='b' then x:=x+y
else if vvod='c' then begin
t:=x;
x:=y;
y:=t;
end
else writeln('vvod neveren');
writeln('x=',x,' y=',y);
readln;
end.
var
x,y,t:integer;
vvod:char;
begin
readln(x,y);
readln(vvod)
if vvod='a' then x:=x-y
else if vvod='b' then x:=x+y
else if vvod='c' then begin
t:=x;
x:=y;
y:=t;
end
else writeln('vvod neveren');
writeln('x=',x,' y=',y);
readln;
end.