View Compilation Error

0_0_38352067_10834.c: In function 'main':
0_0_38352067_10834.c:4:2: error: expected expression before '/' token
  //int a, b, c, d;
  ^
0_0_38352067_10834.c:8:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for (int i = 1; i <= N; i++) {
   ^
0_0_38352067_10834.c:8:3: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code