\[\boxed{\text{561\ (561).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[c_{1} = - 1,\ \ c_{2} = 0,\ \ c_{3} = - 1,\ \ \]
\[c_{4} = 0,\ \ c_{5} = - 1,\]
\[c_{6} = 0,\ \ c_{7} = - 1,\ \ c_{8} = 0,\ \ \]
\[c_{25} = - 1,\ \ c_{200} = 0,\]
\[c_{253} = - 1,\ \ c_{2k} = 0,\ \ \]
\[c_{2k + 1} = - 1.\]