View Compilation Error

0_0_4831765_30333.cpp:2: error: `n' was not declared in this scope
0_0_4831765_30333.cpp:3: error: expected `,' or `;' before '{' token
0_0_4831765_30333.cpp:20: error: `main' must return `int'
0_0_4831765_30333.cpp: In function `int main(...)':
0_0_4831765_30333.cpp:24: error: `fun' cannot be used as a function