Computer, a control method and control program

A player to facilitate the player's operation input at which to synthesize one or more second game medium carrying the first game content. A computer, first game content information, and the first attribute information respectively synthesized in the game medium to change the parameter value is set at least one second game having a parameter value storing information of the medium, the progress of the game based on an instruction from the player. The computer receives an instruction from the player for the synthesis of one or more second game medium to the first game content specified by the player, in response to the instruction, the attribute information of the second game media player possessed based on, among the second game content player possessed, it selects the second game medium and the number required for changing the parameter values ​​of the first game medium specified in more specific level , it generates information for notifying the number and second game contents selected by the player. .FIELD 7