/in/foo.c: In function 'main':
/in/foo.c:7:7: error: stray '\357' in program
  scanf（"%d,%d",&a,&n);
       ^
/in/foo.c:7:8: error: stray '\274' in program
  scanf（"%d,%d",&a,&n);
        ^
/in/foo.c:7:9: error: stray '\210' in program
  scanf（"%d,%d",&a,&n);
         ^
/in/foo.c:7:2: warning: statement with no effect [-Wunused-value]
  scanf（"%d,%d",&a,&n);
  ^~~~~
/in/foo.c:7:10: error: expected ';' before string constant
  scanf（"%d,%d",&a,&n);
          ^~~~~~~
/in/foo.c:7:23: error: expected statement before ')' token
  scanf（"%d,%d",&a,&n);
                       ^
/in/foo.c:5:11: warning: unused variable 'n' [-Wunused-variable]
     int a,n,i=1,Sn=0,tn=0;
           ^