/in/foo.cc: In function 'int main()':
/in/foo.cc:25:13: warning: statement has no effect [-Wunused-value]
     x1++; y1;  int flag1=1;
             ^
/in/foo.cc:33:13: warning: statement has no effect [-Wunused-value]
     x2++; y2;  int flag2=1;
             ^