if else statement in Java not changing variable

Question

//This program should return the total pizza bill according to the chosen option and size of pizza but //all I get is totalPizzaBill =0 every time. I am unable to understand where I am wrong

if(pizzaChoice == 1)
    {
        if(pizzaSize == "L")
            totalPizzaBill = 450;
        else if(pizzaSize == "M")
            totalPizzaBill = 350;
        else if(pizzaSize=="R")
            System.out.println("NA");
    }
    else if(pizzaChoice == 2)
    {
        if(pizzaSize == "L")
            totalPizzaBill = 400;
        else if(pizzaSize == "M")
            totalPizzaBill = 300;
        else if(pizzaSize=="R")
            System.out.println("NA");
    }
    else if(pizzaChoice == 3)
    {
        if(pizzaSize == "L")
            totalPizzaBill = 450;
        else if(pizzaSize == "M")
            totalPizzaBill = 350;
        else if(pizzaSize=="R")
            totalPizzaBill = 250;
    }
    else if(pizzaChoice == 4)
    {
        if(pizzaSize == "L")
            totalPizzaBill = 400;
        else if(pizzaSize == "M")
            totalPizzaBill = 300;
        else if(pizzaSize=="R")
            totalPizzaBill = 200;
    }
    else if(pizzaChoice == 5)
    {
        if(pizzaSize == "L")
            totalPizzaBill = 500;
        else if(pizzaSize == "M")
            totalPizzaBill = 375;
        else if(pizzaSize=="R")
            totalPizzaBill = 175;
    }