#include<stdio.h>
#include<string.h>
int main()
  char signal[20];
  scanf("%s",signal);
  if(strcmp(signal,"Red")===0){
      printf("Stop");
  }
  else if(strcmp(signal,"Yellow")===0){
      printf("Ready");
  }
  else if(strcmp(signal,"Green")===0){
      printf("Go");
  }
  else{
      printf("Invalid input");
       }
       return 0;
       }