/in/foo.cc: In function 'int Sr(int)':
/in/foo.cc:14:9: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return s;
         ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:20:17: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if(Sr(m)==Sr(n)&&Sr(m)==m+n+1)
     ~~~~~~~~~~~~^~~~~~~~~~~~~~
/in/foo.cc:20:17: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
/in/foo.cc:20:17: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]