#include <stdio.h>
#include <string.h>

int main(){
    cher s[20];
    scanf("%s", s);
    
    if (strcmp(s, "Red") == 0)
        printf("Stop");
    else if (strcmp(s, "Yellow") == 0)
        printf("Ready");
    else if (strcmp (s, "Green") == 0)
        print("Go");
    else 
        printf ("Invalid input");
    return 0;
    
}