error: expected primary-expression before '<<' token

#include <iostream>
int main()
{
    int a, b = 7;
    int c, d = 5;
    int Obwod = 24;
   
    a = b = 7;
    c = d = 5;
    Obwod = 24;
   
    std::cout << "Dlugosc boku a prostokata: " << a << std::endl;
    std::cout << "Dlugosc boku b prostokata: " << b << std::endl;
    std::cout << "Dlugosc boku c prostokata: " << c << std::endl;
    std::cout << "Dlugosc boku d prostokata: " << d << std::endl;
    std::cout << "Obwod = " << Obwod = << std::endl; //W tym wierszu pokazuje błąd
    return 0;
}

#include <iostream>
int main()
{
    int a, b = 7;
    int c, d = 5;
    int Obwod = 24;
   
    a = b = 7;
    c = d = 5;
    Obwod = 24;
   
    std::cout << "Dlugosc boku a prostokata = " << a << std::endl;
    std::cout << "Dlugosc boku b prostokata = " << b << std::endl;
    std::cout << "Dlugosc boku c prostokata = " << c << std::endl;
    std::cout << "Dlugosc boku d prostokata = " << d << std::endl;
    std::cout << "Obwod = " << Obwod << std::endl;
    return 0;
}