#include <stdio.h>
#include <string.h>
#include <math.h>

int main(void) {
char pi_form[10] = "\0";
int i;
for (i=0;i<7;i+=2) {
sprintf(pi_form, "%%.%dlf", i);
printf("Format %s -> ", pi_form);
strcat(pi_form, "\n");
printf(pi_form, M_PI);
}
return 0;
}