/in/foo.cc: In function 'int main()':
/in/foo.cc:36:9: error: 'i' was not declared in this scope
     For(i,0,10)tw[i]=1<<i;
         ^
/in/foo.cc:36:15: error: 'For' was not declared in this scope
     For(i,0,10)tw[i]=1<<i;
               ^