\[\boxed{\mathbf{387.}}\]
\[46 + 358 = 404\]
\[358 + 46 = 404\]
\[87 + 139 = 226\]
\[139 + 87 = 226\]
\[5 + 496 = 501\]
\[496 + 5 = 501\]
\[9 + 795 = 804\]
\[795 + 9 = 804\]
\[372 + 428 = 800\]
\[428 + 372 = 800\]
\[604 + 209 = 813\]
\[209 + 604 = 813\]
\[583 + 417 = 1000\]
\[417 + 583 = 1000\]
\[128 + 872 = 1000\]
\[872 + 128 = 1000\]