let input:[Int64] = readLine()!.split(separator: " ").map{Int64($0)!}
//let output:Int64 = (input[0] * input[1] * input[2]) % input[3]
var output:Int64
output = input[0] * input[1]
output = output % input[3]
output = output * input[2]
output = output % input[3]
print(output)