C언어로 ppm 수정좀 하려그러는뎁

[잉호(210.104)]

#include<stdio.h>

int main(void){

        FILE*fp;

        int i,j;

        fp=fopen("out.ppm","w");

        fprintf(fp,"P3\n100 100\n255\n");

        for(i=0;i<100;i++){

                for(j=0;j<100;j++){

                        fprintf(fp,"7 1 132 ");

                }

                fputs("",fp);

        }

        fclose(fp);

        return 0;

}

왜 코드를 저렇게 짜면

ppm파일에서 앞부분이 꺼멓게 죽지??