y;f(n){for(y=0;n>y*++y/2;);return(int)pow(y-1,n+y*(3-y)/2-1);}

main(){
printf("1 -> %d\n",f(1));
printf("2 -> %d\n",f(2));
printf("3 -> %d\n",f(3));
printf("5 -> %d\n",f(5));
printf("10 -> %d\n",f(10));
printf("12 -> %d\n",f(12));
printf("15 -> %d\n",f(15));
}