View Compilation Error

0_0_8374163_11192.cpp: In function `int build_tree(int, int, int)':
0_0_8374163_11192.cpp:20: error: `Return' undeclared (first use this function)
0_0_8374163_11192.cpp:20: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_8374163_11192.cpp:20: error: expected `;' before "node"