  Let $A$ be an integral nonnegative $m\times n$ matrix, $b$ be an integral
nonnegative vector. It is suggested new method for reduction of integer program
$\max \{cx| Ax=b, x\ge 0, x\in\mathbf{Z}^n\}$ to knapsack problem $\max \{c'x|
fAx=fb, x\ge 0, x\in\mathbf{Z}^n\}$.
