#include <stdio.h> #include <math.h> int main() { int x1,y1,x2,y2; scanf("%d %d\n %d %d",&x1,&y1,&x2,&y2); double E,M,D; E=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)); M=sqrt((x1-x2)*(x1-x2))+sqrt((y1-y2)*(y1-y2)); D=sqrt((M-E)*(M-E)); printf("%lf",D); retur...