#include <stdio.h>

f(x){return(x&~0U/3*2)/2+(x&~0U/3)*2;}

int main (int argc, char **argv) {
    int i;
    int testcases[] = {0, 1, 9, 85, 220, 1827, 47525};

    for (i = 0; i < (sizeof(testcases) / sizeof(testcases[0])); i++) {
        printf("f(%d)=%d\n", testcases[i], f(testcases[i]));
    }
    return 0;
}