// editor4
#include<stdio.h>
int main()
{
    int StudentScore;
    scanf("%d", &StudentScore)
    if(StudentScore < 0)
    {
        printf("Invalid input\n");
    }
    else if(StudentScore > 75)
    {
        printf("Great job!\n");
    }
    else if(StudentScore >= 50 && StudentScore <= 75)
    {
        printf("Good effort!\n");
    }
    else
    {
        printf("Keep trying!\n");
    }
    return 0;
}