Let $\mathrm{A}=\left\{1, \mathrm{a}_1, \mathrm{a}_2 \ldots . . \mathrm{a}_{18}, 77\right\}$ be a set of integers with $1<\mathrm{a}_1<\mathrm{a}_2<\ldots<\mathrm{a}_{18}<77$. Let the set $\mathrm{A}+\mathrm{A}=\{\mathrm{x}+\mathrm{y}: \mathrm{x}$, $y \in A\}$ contain exactly 39 elements. Then, the value of $a_1+a_2+\ldots+a_{18}$ is equal to $\_\_\_\_$ .