Challenge: Traffic Light

Lab C Intermediate 20 points

Use typedef enum { RED, GREEN, YELLOW } Light;. The light starts at RED, and every tick it changes RED → GREEN → YELLOW → RED. Read a number of ticks n and print the name of the light after each tick, one per line.

Input

One integer n (1 ≤ n ≤ 20).

Output

n lines with RED, GREEN or YELLOW.

Example

Input

Output

GREEN
YELLOW
RED
GREEN

Sample input available Sample output available

Editor

Hints

Each tick: work out the next light from the current one.

Then print its name with if/else or switch.

Solution explanation

The enum keeps track of the state, and each tick moves it to the next state in the cycle.

Show solution

#include <stdio.h>

typedef enum { RED, GREEN, YELLOW } Light;

int main() {
    int n;
    scanf("%d", &n);
    Light now = RED;
    for (int i = 0; i < n; i++) {
        if (now == RED) {
            now = GREEN;
        } else if (now == GREEN) {
            now = YELLOW;
        } else {
            now = RED;
        }
        if (now == RED) {
            printf("RED\n");
        } else if (now == GREEN) {
            printf("GREEN\n");
        } else {
            printf("YELLOW\n");
        }
    }
    return 0;
}

Output

Answer