{"raw_statement":[{"iden":"problem statement","content":"_ButCoder Inc._ runs a programming competition site called _ButCoder_. In this site, a user is given an integer value called rating that represents his/her skill, which changes each time he/she participates in a contest. The initial value of a new user's rating is $0$, and a user whose rating reaches $K$ or higher is called _Kaiden_ (\"total transmission\"). Note that a user's rating may become negative.\nHikuhashi is a new user in ButCoder. It is estimated that, his rating increases by $A$ in each of his odd-numbered contests (first, third, fifth, ...), and decreases by $B$ in each of his even-numbered contests (second, fourth, sixth, ...).\nAccording to this estimate, after how many contests will he become Kaiden for the first time, or will he never become Kaiden?"},{"iden":"constraints","content":"*   $1 ≤ K, A, B ≤ 10^{18}$\n*   All input values are integers."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$K$ $A$ $B$"},{"iden":"sample input 1","content":"4000 2000 500"},{"iden":"sample output 1","content":"5\n\nEach time Hikuhashi participates in a contest, his rating is estimated to change as $0$ → $2000$ → $1500$ → $3500$ → $3000$ → $5000$ → $…$ After his fifth contest, his rating will reach $4000$ or higher for the first time."},{"iden":"sample input 2","content":"4000 500 2000"},{"iden":"sample output 2","content":"\\-1\n\nEach time Hikuhashi participates in a contest, his rating is estimated to change as $0$ → $500$ → $-1500$ → $-1000$ → $-3000$ → $-2500$ → $…$ He will never become Kaiden."},{"iden":"sample input 3","content":"1000000000000000000 2 1"},{"iden":"sample output 3","content":"1999999999999999997\n\nThe input and output values may not fit into $32$\\-bit integers."}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}