Suppose the demand for a new pharmaceutical drug, on which the manufacturer has a patent monopoly, is given by \( Q = (100 - P)A^{0.5 \), where \( Q \) is output, \( P \) is the price and \( A \) is advertising expenditure. Production cost of the patented drug is given by \( C(Q) = 60Q \). At the firm’s optimal choices, the ratio of advertising expenditure to sales revenue for the pharmaceutical product will be 1: _________ (in integer).}