#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

int main(int argc, char** argv)
{
    uint32_t f, s, t, x;
    uint64_t m;

    if(argc > 1 && (x = atoi(argv[1])) > 0)
    {
        f = 0;
        s = 1;
        t = 0;
        m = 1;

        for(;;)
        {
            t = f + s;
            f = s;
            s = t;

            if(s >= x) { break; }

            m += s;
        }

        printf("Sum: %llu\n", m);
    }

    return 0;
}