According to the theory of relativity, as objects with mass approach the speed of light, their relative velocities do not simply add up in the way classical Newtonian mechanics would suggest. Instead, their velocities combine according to a formula derived from special relativity.
In the case you described, where two objects are traveling towards each other at the speed of light, it is not possible to apply the formula directly because it involves velocities greater than the speed of light, which violates the principles of special relativity.
According to special relativity, as an object with mass approaches the speed of light, its relativistic mass increases, and its energy requirements to accelerate further also increase. As the object approaches the speed of light, its mass and energy requirements approach infinity, making it impossible for an object with mass to reach or exceed the speed of light.
Therefore, it is not valid within the framework of special relativity to consider two objects traveling towards each other at the speed of light.