I use this code to resolve the problem, but it has RunTime error, but why? i'm doing just a casting and inPyCharm is alright

from math import sqrt x1 = float(input()) y1 = float(input()) x2 = float(input()) y2 = float(input())

print(f'{round(sqrt((x2 - x1) 2 + (y2 - y1) 2), 4)}')