View Compilation Error

0_0_31710882_18972.cpp: In function 'long long int Lucas(int, int)':
0_0_31710882_18972.cpp:42:11: error: a function-definition is not allowed here before '{' token
 int main(){
           ^
0_0_31710882_18972.cpp:53:1: error: expected '}' at end of input
 }
 ^