#include <stdio.h>

int main()
{
    int i;
    int v1[10] = {10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
    int v2[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
    int v3[20];

    for (i = 0; i < 10; ++i) {
        v3[2*i  ] = v1[i];
        v3[2*i+1] = v2[i];
    }

    for (i = 0; i < 20; ++i)
        printf("%d ", v3[i]);
    printf("\n");
    
    return 0;
}