Mi a hiba a c++ programkódban?

int main()

{

srand(time(0));

long double a,b;

char v,w;

do{

cout << "a erteke:";

cin >> a;

cout << "b erteke:";

cin >> b;

cout << "Milyen muveletet szeretne elvegezni(+,-,*,/)";

cin >> w;

if(w=='+'){

cout << "a+b=" << a+b;}

else{if(w=='-'){

cout << "a-b=" << a-b;}

else{if(w=='*'){

cout << "a*b=" << a*b;}

if(w=='/'){

cout << "a/b=" << a/b;}

cout << "Szeretne meg szamolni? (i/n)";

cin >> v;}

while(v=='i');

return(0);

}