Students are standing in a line to get tested for corona. Yeonji stands right behind Jeongsu, Jeongsu stands 24th from the back, and Yeonji stands 18th from the front. Find how many students are in line.
18 24 [OP_ADD]
var_a = 18
var_b = 24
var_c = var_a + var_b
print(int(var_c))