Transforming one-hot encoded variable to one column

I have age columns like so that are dummy encoded. How can transform these columns to one column using dplyr?

Input:

  age_0-10 age_11-20 age_21-30 age_31-40 age_41-50 age_51-60 gender
1 0        1         0         0         0         0         0
2 0        0         1         0         0         0         1
3 0        0         0         1         0         0         0
4 0        1         0         0         0         0         1
5 0        0         0         0         0         1         1

Expected Output:

age         gender 
1 11-20     0   
2 21-30     1
3 31-40     0
4 11-20     1
5 51-60     1 

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