View Compilation Error

0_0_27477658_6834.c: In function 'main':
0_0_27477658_6834.c:14:5: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
     for (int i = 2; i <= step; i++)
     ^
0_0_27477658_6834.c:14:5: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_27477658_6834.c:20:13: error: expected expression before '/' token
             // printf("%d\n", i);
             ^
0_0_27477658_6834.c:24:9: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
         for (int j = i; j <= step; j += i)
         ^