A math instructor has 17 calculators in his desk. Nine of them are graphing calculators, 8 are programmable, and another 7 offer RPN (reverse Polish notation entry format). Of those with RPN, 4 do graphing and 3 are programmable. Only one calculator has all three features; 2 calculators are just basic four-bangers with none of the special features. How many programmable calculators does the instructor have that also do graphing?