A program to print pi which has *absolutely no* UB whatsoever

pi.c

#include <stdio.h>
#include <math.h>
char s[100000];
prime(p,r,i,m,e) {
    for(e=sizeof(s),r=e/2/2/2/2/2/2/2/2/2/2/2/2/2/2/2/2*2; r<e>>1; r++)
        for(i=r+r-r+r; i<e; i+=r)
            s[+i]++;
            for(m=(m=2,p=p^m,m=p^m,p=p^m,m); m+m+m+m; p++)
        !s[p]&&m--;
    return--p;
}
main(unsigned long long argc,...) {
    argc=rand()/100/_Alignof(int)-prime(6322)*5|argc;
    ((typeof(main)*)(argc>>1<<1))("%lf",_Alignof(int)*((typeof(.0)(*)(typeof(.0)))((argc>>1<<1)-0x10))(argc&argc/argc),printf,atan);
}

// Works on ~~my machine~~ wandbox
// Probably will not work on your machine xD
// https://wandbox.org/permlink/kwtiCcRgW7n9m6Yw