Answer the questions based on the information given below. Nine persons R, S, T, U, V, W, X, Y and Z live in a family of three generations. V is married to S. W is the son of S and sibling of Z. Z is the mother-in-law of Y. R is the only grandchild of S. R is a male member. T is the son of X and father of R. I has two married children. How many male members are there in the family?