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

void multiconc(char *combined, ...) {
    va_list args;
    va_start(args, combined);
    const char *t;
    combined[0] = '\0';
    while((t = va_arg(args, const char*)) != NULL) {
        strcat(combined, t);
    }
    va_end(args);
}

int main(){
  char cel[256];

  multiconc(cel, "slowo1 ", "slowo2-", "slowo3 ");

  printf("%s\n", cel);
}