/in/foo.c: In function 'main':
/in/foo.c:4:44: warning: unused variable 's' [-Wunused-variable]
  int n,m,a[500000],b[500000],w[500000],i,j,s=0,Q=0,max;
                                            ^
/in/foo.c:22:8: warning: 'max' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d",max);
        ^