View Compilation Error

0_0_19989179_9744.cpp: In function 'int main()':
0_0_19989179_9744.cpp:17:6: error: 'i' was not declared in this scope
 for( i=1;i<=n;i++)
      ^
0_0_19989179_9744.cpp:20:6: error: 'i' was not declared in this scope
 for( i=2;i<=n;i++)
      ^