No testdata at current.

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

int l;
char s[105];

int main() {
    while (~scanf("%s",s)) {
        l=strlen(s);
        putchar(s[0]);
        for (int i=1; i<l; ++i) {
            if (isdigit(s[i])^isdigit(s[i-1]))
                putchar(' ');
            putchar(s[i]);
        }
        putchar(' ');
    }
    return 0;
}