/in/foo.c: In function 'aa':
/in/foo.c:9:11: error: invalid operands to binary % (have 'long int' and 'double')
    i = i*a%A;
           ^
/in/foo.c:10:10: error: invalid operands to binary % (have 'long int' and 'double')
   a = a*a%A;
          ^
/in/foo.c: In function 'main':
/in/foo.c:18:2: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'long int *' [-Wformat=]
  scanf("%d", &b);
  ^
/in/foo.c:19:2: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long int' [-Wformat=]
  printf("%d\n", aa(b));
  ^