foo.c: In function 'main':
foo.c:26:4: error: invalid operands to binary - (have 'int' and 'int *')
foo.c:35:1: warning: format '%d' expects argument of type 'int', but argument 2 has type 'int *' [-Wformat]
foo.c:4:15: warning: variable 'y' set but not used [-Wunused-but-set-variable]