I want to do a for loop and explain it here by simple print function. I want change the data printed after a fixed value. Let's regard this code:

```
for i in range (7):
    print (i, i+15, i+1)

```

it gives me:

```
0 15 1
1 16 2
2 17 3
3 18 4
4 19 5
5 20 6
6 21 7

```

But I want to add `1` to the printed values of the second row after each `3` interation. I mean from the first to third iteration, I want the same results as printed above. But from third to sixth I want to add `1` to `i+15` (printing `i+16` rather than `i+15`). Then again after the sixth row, I want to add `1` to `i+16` (printing `i+17` rather than `i+16` or `i+15`). I mean I want to have this one:

```
0 15 1
1 16 2
2 17 3
3 19 4
4 20 5
5 21 6
6 23 7

```

How can I make my `i` in the function to e such a thing? Itried the following but it gives another thing:

```
for i in range (7):
    if i % 3 == 0:
        print (i, i+15+1, i+1)
    else:
        print (i, i+15, i+1)

```

I do appreciate any help in advance.