#include<stdio.h>

int main(){
    char[10] = s;
    
    fgets(sizeof(s),s);
    
    if ( s == "Red"){
        printf("Stop");
    }else if( s == "Yellow"){
        printf("Ready");
    }else if( s == "Green"){
        printf("Go");
    }else{
        printf("Invalid input");
    }
    return 0;
}