A company is considering to take a $3$ year project to develop a new product with $$30$ million initial cost. If the demand is high, the project will generate cash flow of $$20$ million each year. If the demand is average, the project will generate cash flow of $$15$ million each year. If the demand is low, the project will generate cash flow of $$5$ million each year. The cost of capital for the project is $10\%.$ The probability of high demand, average demand, and low demand are $20\%,60\%$ and $20\%$ respectively. After $3$ years, customer tastes will change and the first generation product will be terminated. The company will be able to launch a second$-$generation product if demand for the original product is average or above. This second$-$generation product should have the same expected cash flow and risk level as first generation products. What is the input for stock price $($S$)$ to estimate growth option value using Black Scholes model?