/in/foo.c: In function 'main':
/in/foo.c:7:15: warning: use of 'll' length modifier with 'f' type character has either no effect or undefined behavior [-Wformat=]
     scanf("%llf %llf %llf",&a,&b,&c);
               ^
/in/foo.c:7:20: warning: use of 'll' length modifier with 'f' type character has either no effect or undefined behavior [-Wformat=]
     scanf("%llf %llf %llf",&a,&b,&c);
                    ^
/in/foo.c:7:25: warning: use of 'll' length modifier with 'f' type character has either no effect or undefined behavior [-Wformat=]
     scanf("%llf %llf %llf",&a,&b,&c);
                         ^
/in/foo.c:12:18: warning: use of 'll' length modifier with 'f' type character has either no effect or undefined behavior [-Wformat=]
     printf("%.0llf",b+(c-1)/2);
                  ^