Solve the programming task below in a Python markdown code block.
Read problem statements in [Bengali], [Mandarin Chinese], [Russian], and [Vietnamese] as well.

Chef is going on a road trip and needs to apply for inter-district and inter-state travel e-passes. It takes A minutes to fill each inter-district e-pass application and B minutes for each inter-state e-pass application.

His journey is given to you as a binary string S of length N where 0 denotes crossing from one district to another district (which needs an inter-district e-pass), and a 1 denotes crossing from one state to another (which needs an inter-state e-pass).

Find the total time Chef has to spend on filling the various forms.

------ Input Format ------ 

- The first line of the input contains a single integer T denoting the number of test cases. The description of T test cases follows.
- Each test case contains two lines of input.
- First line contains three space separated integers N, A and B.
- Second line contains the string S.

------ Output Format ------ 

For each testcase, output in a single line the total time Chef has to spend on filling the various forms for his journey.

------ Constraints ------ 

$1 ≤ T ≤ 10^{2}$
$1 ≤ N, A, B ≤ 10^{2}$
$S_{i} \in \{'0', '1'\}$

------ subtasks ------ 

Subtask #1 (100 points): original constraints

----- Sample Input 1 ------ 
3
2 1 2
00
2 1 1
01
4 2 1
1101
----- Sample Output 1 ------ 
2
2
5
----- explanation 1 ------ 
Test case $1$: Chef needs total $2$ inter-district e-passes, and he will be filling them in total $1 \cdot 2 = 2$ minutes.

Test case $3$: Chef needs total $1$ inter-district e-pass and $3$ inter-state e-passes, and he will be filling them in total $2 \cdot 1 + 1 \cdot 3 = 5$ minutes.