888B - Buggy Robot - CodeForces Solution

def solve():
    n = int(input().strip())
    arr = input().split()[0]
    up_down = 0
    left_right = 0
    
    for i in range(0,n):
        if arr[i] == 'U':
            up_down += 1
        elif arr[i] == 'D':
            up_down -= 1
        elif arr[i] == 'L':
            left_right += 1
        elif arr[i] == 'R':
            left_right -= 1
        else:
            continue

    print(n-abs(up_down)-abs(left_right))

solve()