/in/foo.c: In function 'main':
/in/foo.c:6:5: error: 'i' undeclared (first use in this function)
     i==x+y;
     ^
/in/foo.c:6:5: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:7:16: error: expected ')' before 'i'
     printf("%d"i);
                ^
/in/foo.c:7:14: warning: format '%d' expects a matching 'int' argument [-Wformat=]
     printf("%d"i);
              ^