Javier designs leather shoes in his workshop. he charges $45 for women's shoes and $50 for mens shoes. he needs to make $2,500 per week to meet his expenses. this situation can be given by 45 x plus 50 y equals 2500, where x is the number of women shoes and y is the number of mens shoes designed. if he does not have any female customers during a particular week, how many male customers does he need to meet his expenses? (x > or equal to 0, y > or equal to 0, and y take only integer values)