View Compilation Error

0_0_15536940_6965.c: In function 'main':
0_0_15536940_6965.c:11:5: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
     for(int i=3;i<=1000001;i++)
     ^
0_0_15536940_6965.c:11:5: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_15536940_6965.c:39:9: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
         for(int i=n;i<=m;i++)
         ^