How to input the given word line into different strings seperated by space?

I am new to c++ and finding it difficult to use strings.User is inputting his full name i.e firstname and lastname seprated by space and i want to store it in different strings while he inputs his name

Input

ABC XYZ

Code

    string s1,s2;
    getline(cin,s1);

    getline(cin,s2);
    cout<<"Firstname :"s1<<endl;
    cout<<"Lastname :"s2<<endl;

Output

Firstname :ABC XYZ
Lastname :                //nothing is printed here , i want to sore the last name here