#include <stdio.h>

int main() {

    int a[4] = {20, 1, 2, 3}; // directly
    int a[10] = {1, 2, 3, 4, 5}; //partly

    int a[] = {1, 3, 4, 5, 6}; // == int a[5] = {1, 3, 4, 5, 6}

    

    return 0;
}