#include <stdio.h> int main() { int x1 = 0; int y1 = 0; int x2 = 0; int y2 = 0; scanf("%d %d", &x1, &y1); scanf("%d %d", &x2, &y2); printf("%d\n", (x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); return 0; }