balayage a 1 b 2 x a k 1 n 1 h POWER 10 NEG k x a WHILE LT POWER x 2 2 x ADD x h a MINUS 1 x 1 h 0 DIVIDE 1 ROUND MULTIPLY 1 MINUS 1 x 1 h 1 POWER 10 1 n 1 POWER 10 1 n 0 DIVIDE 1 ROUND MULTIPLY 1 x 1 POWER 10 1 n 1 POWER 10 1 n 0 7