  Given $N$ positive integers $a_1, ..., a_N$ with $\gcd(a_1, ..., a_N)=1$, let
$f_N$ denote the largest natural number which is not a positive integer
combination of $a_1, ..., a_N$. This paper gives an optimal lower bound for
$f_N$ in terms of the absolute inhomogeneous minimum of the standard
$(N-1)$-simplex.
