/in/foo.c: In function 'main':
/in/foo.c:6:7: error: stray '\357' in program
  scanf（"%f%f",&a,&b）;
       ^
/in/foo.c:6:8: error: stray '\274' in program
  scanf（"%f%f",&a,&b）;
        ^
/in/foo.c:6:9: error: stray '\210' in program
  scanf（"%f%f",&a,&b）;
         ^
/in/foo.c:6:2: warning: statement with no effect [-Wunused-value]
  scanf（"%f%f",&a,&b）;
  ^~~~~
/in/foo.c:6:10: error: expected ';' before string constant
  scanf（"%f%f",&a,&b）;
          ^~~~~~
/in/foo.c:6:22: error: stray '\357' in program
  scanf（"%f%f",&a,&b）;
                      ^
/in/foo.c:6:23: error: stray '\274' in program
  scanf（"%f%f",&a,&b）;
                       ^
/in/foo.c:6:24: error: stray '\211' in program
  scanf（"%f%f",&a,&b）;
                        ^
/in/foo.c:8:11: warning: format '%f' expects argument of type 'double', but argument 2 has type 'int' [-Wformat=]
  printf("%f\n",sum);
           ^