View Compilation Error

0_0_20096621_8596.c: In function 'main':
0_0_20096621_8596.c:10:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int n1 = 1; n1 <= n; ++n1)
  ^
0_0_20096621_8596.c:10:2: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_20096621_8596.c:15:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for(int n2 = 0; n2 < 10; ++n2)
   ^