I need help with this problem please

An investor plans to invest 35 percent of her funds in the common stock of Mickey Company and 65 percent in Mini Company. The expected return on Mickey is 16 percent and the expected return on Mini is 12 percent. The standard deviation of returns for Mickey is 15 percent and for Mini is 28 percent. The correlation between the returns for Mickey and Mini is -0.6 (negative 0.6) . Determine the standard deviation of returns for this investor's portfolio.