View Compilation Error

0_0_12357137_1480.cpp:3: error: expected constructor, destructor, or type conversion before "namespace"
0_0_12357137_1480.cpp:3: error: expected `,' or `;' before "namespace"
0_0_12357137_1480.cpp:5: error: expected constructor, destructor, or type conversion before '<' token
0_0_12357137_1480.cpp:5: error: expected `,' or `;' before '<' token
0_0_12357137_1480.cpp: In function `int main()':
0_0_12357137_1480.cpp:18: error: `a' undeclared (first use this function)
0_0_12357137_1480.cpp:18: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_12357137_1480.cpp:23: error: expected `;' before '}' token
0_0_12357137_1480.cpp:24: error: `sort' undeclared (first use this function)