View Compilation Error

0_0_9138144_31173.cpp:6: error: expected constructor, destructor, or type conversion before "namespace"
0_0_9138144_31173.cpp:6: error: expected `,' or `;' before "namespace"
0_0_9138144_31173.cpp: In function `long long int cost(long long int, long long int, long long int)':
0_0_9138144_31173.cpp:23: error: `min' undeclared (first use this function)
0_0_9138144_31173.cpp:23: error: (Each undeclared identifier is reported only once for each function it appears in.)