Language: C

#include<stdio.h>
#include<math.h>
int main() {
&#160;&#160;float x1, x2, y1, y2;
&#160;&#160;&#160;
&#160;&#160;scanf("%f %f %f %f", &x1, &x2, &y1, &y2);
&#160;&#160;printf("%.8f\n", sqrt((float)pow((float)(x1 - y1), 2) + (float)pow((float)(x2 - y2), 2)));
&#160;&#160;&#160;
&#160;&#160;return 0;
}

Compiler output:
main.c: In function 'main':
main.c:4:2: error: stray '#' in program
    4 | &#160;&#160;float x1, x2, y1, y2;
      |  ^
main.c:4:1: error: lvalue required as unary '&' operand
    4 | &#160;&#160;float x1, x2, y1, y2;
      | ^
main.c:4:8: error: stray '#' in program
    4 | &#160;&#160;float x1, x2, y1, y2;
      |        ^
main.c:4:7: error: lvalue required as unary '&' operand
    4 | &#160;&#160;float x1, x2, y1, y2;
      |       ^
main.c:5:2: error: stray '#' in program
    5 | &#160;&#160;&#160;
      |  ^
main.c:5:1: error: lvalue required as unary '&' operand
    5 | &#160;&#160;&#160;
      | ^
main.c:5:8: error: stray '#' in program
    5 | &#160;&#160;&#160;
      |        ^
main.c:5:7: error: lvalue required as unary '&' operand
    5 | &#160;&#160;&#160;
      |       ^
main.c:5:14: error: stray '#' in program
    5 | &#160;&#160;&#160;
      |              ^
main.c:5:13: error: lvalue required as unary '&' operand
    5 | &#160;&#160;&#160;
      |             ^
main.c:6:2: error: stray '#' in program
    6 | &#160;&#160;scanf("%f %f %f %f", &x1, &x2, &y1, &y2);
      |  ^
main.c:6:1: error: lvalue required as unary '&' operand
    6 | &#160;&#160;scanf("%f %f %f %f", &x1, &x2, &y1, &y2);
      | ^
main.c:6:8: error: stray '#' in program
    6 | &#160;&#160;scanf("%f %f %f %f", &x1, &x2, &y1, &y2);
      |        ^
main.c:6:7: error: lvalue required as unary '&' operand
    6 | &#160;&#160;scanf("%f %f %f %f", &x1, &x2, &y1, &y2);
      |       ^
main.c:7:2: error: stray '#' in program
    7 | &#160;&#160;printf("%.8f\n", sqrt((float)pow((float)(x1 - y1), 2) + (float)pow((float)(x2 - y2), 2)));
      |  ^
main.c:7:1: error: lvalue required as unary '&' operand
    7 | &#160;&#160;printf("%.8f\n", sqrt((float)pow((float)(x1 - y1), 2) + (float)pow((float)(x2 - y2), 2)));
      | ^
main.c:7:8: error: stray '#' in program
    7 | &#160;&#160;printf("%.8f\n", sqrt((float)pow((float)(x1 - y1), 2) + (float)pow((float)(x2 - y2), 2)));
      |        ^
main.c:7:7: error: lvalue required as unary '&' operand
    7 | &#160;&#160;printf("%.8f\n", sqrt((float)pow((float)(x1 - y1), 2) + (float)pow((float)(x2 - y2), 2)));
      |       ^
main.c:8:2: error: stray '#' in program
    8 | &#160;&#160;&#160;
      |  ^
main.c:8:1: error: lvalue required as unary '&' operand
    8 | &#160;&#160;&#160;
      | ^
main.c:8:8: error: stray '#' in program
    8 | &#160;&#160;&#160;
      |        ^
main.c:8:7: error: lvalue required as unary '&' operand
    8 | &#160;&#160;&#160;
      |       ^
main.c:8:14: error: stray '#' in program
    8 | &#160;&#160;&#160;
      |              ^
main.c:8:13: error: lvalue required as unary '&' operand
    8 | &#160;&#160;&#160;
      |             ^
main.c:9:2: error: stray '#' in program
    9 | &#160;&#160;return 0;
      |  ^
main.c:9:1: error: lvalue required as unary '&' operand
    9 | &#160;&#160;return 0;
      | ^
main.c:9:8: error: stray '#' in program
    9 | &#160;&#160;return 0;
      |        ^
main.c:9:7: error: lvalue required as unary '&' operand
    9 | &#160;&#160;return 0;
      |       ^