/in/foo.cc: In function 'int main()':
/in/foo.cc:10:11: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
   else if (a[0] == '1')if (b[0] == '9')c = 1;
           ^
/in/foo.cc:9:6: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
   if (a[0] == '2')if (b[0] == 'A')c = 1;
      ^