#include<stdio.h>
#include<string.h>
int main() {
    char message[1100];
    int start,L;
    scanf("%s",message);
    if(scanf("%d", &start) != 1|| sacnf("%d", &L) != 1) {
        printf("Invalid Input");
        return 0;
    }
    int len = streln(message);
    if(start < 0 || start >= len || l < 1|| (start + L) > len) {
        printf(Invalid Input");
        return 0;
    }
    for (int i = start;i < start + L; 1++) {
        printf("%c",message[i]);
    }
    return 0;
}