why getline() function does not work here?

Question

I'm a beginner in programming. While learning tried to write the code below. The problem is when I try to get gamar's surname it does not work it, just skips the line with getline(). But when I comment the lines above getline() it works. Where do I make mistake?

#include <iostream>
#include <string>
#include "class.h"
using std::cout;
using std::endl;
using std::cin;
using std::string;

int main(){
    Person gamar;
    cout<<"Enter Gamar's height: ";
    cin>>gamar.height;
    cout<<"Enter Gamar's weight: ";
    cin>>gamar.weight;
    cout<<"Enter Gamar's surname: ";

    getline(cin,gamar.surname );


    cout<<"Gamar's surname: "<<gamar.surname<<endl;
    cout<<"Gamar's height: "<<gamar.height<<endl;
    cout<<"Gamar's weight: "<<gamar.weight<<endl;  


}

And here is the header file:

using std::string;


class Person{
    public:
        string surname;
        int weight;
        int height;
};