#include<stdio.h>
#include<string.h>
int main()
{
    char s[100];
    scanf("%s",s);
    if(strcmp(s,"Red"))
    {
        printf("Stop");
    }
    else if(strcmp(s,"Green"))
    {
        printf("Go");
    }
    else if(strcmp(s,"Yellow"))
    {
        printf("Ready");
    }
    else{
        printf("Invalid input")
    }
}