/in/foo.cc: In function 'int main()':
/in/foo.cc:14:21: warning: iteration 9 invokes undefined behavior [-Waggressive-loop-optimizations]
       if(30+b>=a[i-1])
                ~~~~~^
/in/foo.cc:12:16: note: within this loop
       for(i=1;i<=10;i++)
               ~^~~~