We prove that for any \documentclass[12pt]{minimal}
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$ \varepsilon > 0 $\end{document} there is \documentclass[12pt]{minimal}
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$ k (\varepsilon) $\end{document} such that for any prime p and any integer c there exist \documentclass[12pt]{minimal}
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$ k \leqq k(\varepsilon) $\end{document} pairwise distinct integers xi with \documentclass[12pt]{minimal}
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$ 1 \leqq x_{i} \leqq p^{\varepsilon}, i = 1, \ldots, k $\end{document}, and such that¶¶\documentclass[12pt]{minimal}
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$ \sum\limits_{i=1}^k {{1}\over{x_i}} \equiv c\quad (\mathrm{mod}\, p). $\end{document}¶¶ This gives a positive answer to a question of Erdös and Graham.