/in/foo.cc: In function 'int main()':
/in/foo.cc:72:8: warning: statement has no effect [-Wunused-value]
   for(i;i>=0;i--)
        ^
/in/foo.cc:7:8: warning: unused variable 'm' [-Wunused-variable]
  int n,m,l,i,s=0,j,k=1,b[1000],c[1000];
        ^