View Compilation Error

0_0_15394025_11979.cpp: In function 'int main()':
0_0_15394025_11979.cpp:7:5: error: 'i' was not declared in this scope
 for(i=1;i<=n;i++)
     ^
0_0_15394025_11979.cpp:12:13: error: 'sum' was not declared in this scope
 printf("%d",sum);
             ^