Your character in an RPG game has G1 gold, S1 silver and B1 bronze coins.
You need G2 gold, S2 silver and B2 bronze coins to buy a new armor.
A bank in the game supports four types of exchange operations:
Return the minimal number of exchange operations required for your character to hold at least G2 gold, at least S2 silver and at least B2 bronze coins. Return -1 if the character does not have enough money for that.
- the bank will give you 9 silver coins in exchange for 1 gold coin
- the bank will give you 1 gold coin in exchange for 11 silver coins
- the bank will give you 9 bronze coins in exchange for 1 silver coin
- the bank will give you 1 silver coin in exchange for 11 bronze coins