answer.code: In function ‘main’:
answer.code:35:9: warning: implicit declaration of function ‘prinf’; did you mean ‘printf’? [-Wimplicit-function-declaration]
   35 |         prinf("-1");
      |         ^~~~~
      |         printf
answer.code:9:5: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
    9 |     scanf("%d",&n);
      |     ^~~~~~~~~~~~~~
answer.code:11:9: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
   11 |         scanf("%d",&a[i]);
      |         ^~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccOfgHiS.o: in function `main':
answer.code:(.text.startup+0x163): undefined reference to `prinf'
collect2: error: ld returned 1 exit status