Write a program that will present a user with a string grid of blocks. Pairs of randomly arranged blocks have the same icon on it lying face down. The user must click a pair of blocks, which reveal their symbol. If the symbol is the same, remove them and continue with next round. If symbols are different, turn them face down and allow the user another turn. The game is over when all pairs have been matched. Count the number of turns taken to find all matching pairs as a score.