/in/foo.cc: In function 'int main()':
/in/foo.cc:32:10: warning: iteration 11 invokes undefined behavior [-Waggressive-loop-optimizations]
   s=s+c[i]*100;
       ~~~^
/in/foo.cc:30:11: note: within this loop
  for(i=0;i<12;i++)
          ~^~~
/in/foo.cc:16:23: warning: iteration 10 invokes undefined behavior [-Waggressive-loop-optimizations]
   b[i]=(b[i-1]+300-a[i])%100;
                    ~~~^
/in/foo.cc:14:11: note: within this loop
  for(i=1;i<12;i++)
          ~^~~