/in/foo.c: In function 'main':
/in/foo.c:34:20: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'int' [-Wformat=]
  int x1,n1;scanf("%d%d",x1,n1);
                    ^
/in/foo.c:34:22: warning: format '%d' expects argument of type 'int *', but argument 3 has type 'int' [-Wformat=]
  int x1,n1;scanf("%d%d",x1,n1);
                      ^
/in/foo.c:36:20: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'int' [-Wformat=]
  int x2,n2;scanf("%d%d",x2,n2);
                    ^
/in/foo.c:36:22: warning: format '%d' expects argument of type 'int *', but argument 3 has type 'int' [-Wformat=]
  int x2,n2;scanf("%d%d",x2,n2);
                      ^
/in/foo.c:34:12: warning: 'x1' is used uninitialized in this function [-Wuninitialized]
  int x1,n1;scanf("%d%d",x1,n1);
            ^~~~~~~~~~~~~~~~~~~
/in/foo.c:34:12: warning: 'n1' is used uninitialized in this function [-Wuninitialized]
/in/foo.c:36:12: warning: 'x2' is used uninitialized in this function [-Wuninitialized]
  int x2,n2;scanf("%d%d",x2,n2);
            ^~~~~~~~~~~~~~~~~~~
/in/foo.c:36:12: warning: 'n2' is used uninitialized in this function [-Wuninitialized]