View Compilation Error

0_0_20171094_29889.cpp:2:11: error: '::main' must return 'int'
 void main()
           ^
0_0_20171094_29889.cpp: In function 'int main()':
0_0_20171094_29889.cpp:6:2: error: expected primary-expression before '}' token
  }
  ^
0_0_20171094_29889.cpp: At global scope:
0_0_20171094_29889.cpp:7:3: error: expected unqualified-id before 'if'
   if(n==0)
   ^
0_0_20171094_29889.cpp:9:3: error: expected unqualified-id before 'else'
   else
   ^