#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
        int a=0, b=0;
        switch(argc)
                case 0: puts("Kein Programmname verfügbar.");
        switch(argc)
        {
                case 3: b = atoi (argv[2]);
                case 2: a = atoi (argv[1]);
                        printf("%d + %d = %d\n.", a, b, a+b);
        }
        return 0;
}