View Compilation Error

0_0_16113607_13131.c: In function 'main':
0_0_16113607_13131.c:33:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for (int i = 0; i < n; i++, x = getchar())
   ^
0_0_16113607_13131.c:33:3: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code