tj

$$\because 11454\bmod10=4\tag{1}$$

$$4\cdot4=16\bmod10=6\tag{2}$$

$$6\cdot4=24\bmod10=4$$

看，又回到了原点，所以，“奇4偶6”

#include<cstdio>
int main() {
    int n,t;
    scanf("%d",&n);
    while(n--) {
        scanf("%d",&t);
        printf("%d\n",(t&1?4:6));
    }
}