#include <stdio.h>
#include <string.h>
int main(){
    char signal[10];
    scanf("%s,signal");
    if(strcmp(signal,"Red")==0){
        printf("Stop\n");
    }else if(strcmp(signal,"Yellow")==0){
        printf("Ready\n");
    }else if(strcmp(signal,"Green")==0){
        printf("Go\n");
    }else{
        printf("Invalid input\n");
    }
    return 0;
}