Add records using PA with variable

I do not have an id to enter a student who is from abroad with Carrera and I want to calculate it using a SELECT in my PA, but it tells me Error Code: 1136. Column count does not match value count at row 1

DELIMITER $
CREATE PROCEDURE agregarEstudiante(in _nombre varchar(50), in _edad int, 
        in _genero varchar(20), in _cum double, in _intereses varchar(50), in _carrera varchar(50))
        BEGIN
            SET @cod = (select codigoCarrera from carrera where nombre = _carrera);
            INSERT INTO estudiante VALUES(null, _nombre, _edad, _genero, _cum, _intereses, @cod);
        END $