View Compilation Error

0_0_15666253_8213.c: In function 'main':
0_0_15666253_8213.c:8:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(long int a = 2; a < u; a++)
  ^
0_0_15666253_8213.c:8:2: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_15666253_8213.c:12:4: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
    for(long int b = 2 * a; b < u; b = b + a)
    ^
0_0_15666253_8213.c:21:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for(long int c = 0; c < n; c++)
   ^
0_0_15666253_8213.c:23:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for(long int d = 0; d < n; d++)
   ^
0_0_15666253_8213.c:29:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for(long int e = 0; e < n; e++)
   ^