How to sum range based on condition

[JackBauer]

Hello Friends,

Please see example file attached example sum until true.xlsx

Suppose we have this data:

Number1 Number2 Number3 Condition
0 0 0 TRUE
0 0 0 FALSE
0 0 0 TRUE
1 0 0 FALSE
0 0 0 TRUE
1 0 0 FALSE
1 0 0 FALSE
0 0 0 TRUE
1 0 0 FALSE
1 0 0 FALSE
0 0 0 TRUE
0 0 0 FALSE
1 0 0 FALSE
0 0 0 TRUE
1 0 0 TRUE

In additional column I need to sum up range of data, but only until next TRUE CONDITION. IT SHOULD LOOK LIKE THIS:

0 0 0 TRUE 0
0 0 0 FALSE
0 0 0 TRUE 1
1 0 0 FALSE
0 0 0 TRUE 1
1 0 0 FALSE
1 0 0 FALSE
0 0 0 TRUE 2
1 0 0 FALSE
1 0 0 FALSE
0 0 0 TRUE 1
0 0 0 FALSE
1 0 0 FALSE
0 0 0 TRUE 0
1 0 0 TRUE 1

I can't figure out a clever way using functions to do it. I hope You will understand, even if I can't explain it very properly.

[Pepe Le Mokko]

Your explanation on the sheet does not match your expected results."In other words - how to sum up a range of cells between two TRUES

So the second TRUE would return0, not 1.
The last TRUE should return 1 but there is nothing between the two last TRUES ?
"

[JackBauer]

Please let me give another example, this time it is more accurate:

ABC TRUE [here sum ABC DEF]
DEF FALSE
GHI TRUE [here sum GHI JKL MNO PQR]
JKL FALSE
MNO FALSE
PQR FALSE
STU TRUE [here sum STU]
VWX TRUE [here sum VWX]

[JackBauer]

Never mind, figured out myself. Used NESTED IF

[Pepe Le Mokko]

It would be nice if you would share your solution with us. Thank you