def p_stmts(p):
 if (len(p) == 3):
  p[0] = (p[1] + p[2])
 else:
  p[0] = p[1]

def p_stmts ( p ) : if ( len ( p ) == 3 ) : p [ 0 ] = ( p [ 1 ] + p [ 2 ] ) else : p [ 0 ] = p [ 1 ]
stmts : stmts stmt | stmt .