does grpc service must have exactly one input parameter and one return value

let's say i have a proto file like this. can I define service like this

rpc SayHello () returns (Response) {} //service has no input
rpc SayHello (Request1,Request2) returns (Response) {}//service has two inputs

//.proto file

syntax = "proto3";

service Greeter{
    rpc SayHello (Request) returns (Response) {}
}


message Request{
    string request = 1;
}

message Response{
    string response = 1;
}