/in/foo.cc:21:18: error: stray '\357' in program
  for(i=N,i>=2;i--；)
                  ^
/in/foo.cc:21:19: error: stray '\274' in program
  for(i=N,i>=2;i--；)
                   ^
/in/foo.cc:21:20: error: stray '\233' in program
  for(i=N,i>=2;i--；)
                    ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:21:11: warning: right operand of comma operator has no effect [-Wunused-value]
  for(i=N,i>=2;i--；)
          ~^~~
/in/foo.cc:21:21: error: expected ';' before ')' token
  for(i=N,i>=2;i--；)
                     ^