#include<stdio.h>
#include<string.h>
int main()
{
    char s[20];
    scanf("%d",s);
    if(strcmp(s,"RED")==0)
    printf("STOP");
    else if(strcmp(s,"YELLOW")==0)
    printf("Ready");
    else if(strcmp(s,"GREEN")==0)
    printf("Go");
    else{
        print("Invalid input");
    }
    return 0;
}