#include <stdio.h>
#include <stdint.h>
int main(void)
{
    size_t mask = (SIZE_MAX/2)+1;
    printf("mask is %lf\n",mask);
    double mantissia=42;
    printf("%zu is the llu of 42.\n",mantissia);
    size_t mant=4631107791820423168;
    printf("%mant is %zu.\n",mant);
    size_t c=mant^mask;
    printf("%lf\n",c);

    return 0;
}