#include <string.h>

#if __GNUC__ < 4
#define restrict
#endif

char *strncat(char *restrict d, const char *restrict s, size_t n)
{
        char *a = d;
        d += strlen(d);
        while (n && *s) n--, *d++ = *s++;
        *d++ = 0;
        return a;
}