#include<stdio.h>
#include<stdlib.h>
#include<string.h>

#define MAX_LINE_LENGTH 200

int main(int argc, char** argv){
    char sep = ',';
    if(argc > 1){
        sep = argv[1][0];
    }

    char line[MAX_LINE_LENGTH];
    fgets(line,MAX_LINE_LENGTH, stdin);
    line[strlen(line)-1] = '\0';
    printf("%s",line);

    while(fgets(line,MAX_LINE_LENGTH, stdin) != NULL){
        line[strlen(line)-1] = '\0';
        printf("%c%s",sep,line);
    }

    printf("\n");


    return 0;
}