View Compilation Error

1_714_1187_28486.c: In function 'main':
1_714_1187_28486.c:7:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int i = 1; i <= n;i++)
  ^
1_714_1187_28486.c:7:2: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
1_714_1187_28486.c:18:6: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
      for(int j = 1; j < k;j++)
      ^