View Compilation Error

0_0_20725864_32762.cpp: In function 'int main()':
0_0_20725864_32762.cpp:11:7: error: 'i' was not declared in this scope
   for(i=0;i<=n;i++)
       ^
0_0_20725864_32762.cpp:12:8: error: 'j' was not declared in this scope
    for(j=1;j*2<=n;j++)
        ^
0_0_20725864_32762.cpp:15:7: error: 'i' was not declared in this scope
   for(i=2;i<=n;i++)
       ^
0_0_20725864_32762.cpp:16:8: error: 'j' was not declared in this scope
    for(j=1;j*2<=i;j++)
        ^