>>268
やりたいのは、こういう事?
http://codepad.org/Bm4ZQ4Fc

入力例:
1:#include <stdio.h>
2:int main()
3:{
4: int n,k;
5: scanf("%d", &n);
6: for (; n > 1; n--) {
7: for (k = n - 1; n % k; k--);
8: if (k == 1)
9: printf("Answer=%d¥n", n);
10: }

出力例:
1: !glajsbc:qrbgm,f<
2: glrk_gl&'
3: y
4: glrl*i9
5: qa_ld& #b *$l'9
6: dmp&9l</9l++'y
7: dmp&i;l+/9l#i9i++'9
8: gd&i;;/'
9: npglrd& ?lqucp;#bZl *l'9
10: {