>>374
#include<stdio.h>
int main(int argc,char* argv[]){FILE* src=stdin;FILE* dst=stdout;int c;
if(argc>=2)src=fopen(argv[1],"r");if(argc==3)dst=fopen(argv[2],"w");
if(argc<4)while((c=fgetc(src))!=EOF)fputc(c,dst);return 0;}