/in/foo.cc: In function 'int main()':
/in/foo.cc:13:8: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
        for (int i=1;i<=20002;i++)
        ^~~
/in/foo.cc:15:9: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
         cout<<tot;
         ^~~~
/in/foo.cc:14:16: warning: iteration 20001 invokes undefined behavior [-Waggressive-loop-optimizations]
         if (a[i]==2) tot++;
             ~~~^
/in/foo.cc:13:22: note: within this loop
        for (int i=1;i<=20002;i++)
                     ~^~~~~~~