/in/foo.c: In function 'main':
/in/foo.c:5:10: warning: unknown conversion type character ',' in format [-Wformat=]
 scanf("d%,d%",&a,&b);
          ^
/in/foo.c:5:12: warning: spurious trailing '%' in format [-Wformat=]
 scanf("d%,d%",&a,&b);
            ^
/in/foo.c:5:7: warning: too many arguments for format [-Wformat-extra-args]
 scanf("d%,d%",&a,&b);
       ^~~~~~~
/in/foo.c:7:10: warning: spurious trailing '%' in format [-Wformat=]
 printf("d%",sum);
          ^
/in/foo.c:7:8: warning: too many arguments for format [-Wformat-extra-args]
 printf("d%",sum);
        ^~~~