#include<stdio.h>
#include<string.h>
int main(){
    char message[10001];
    int start,L;
    fgets(message,sizeof(message),stdin);
    message[strcpn(message,"\n")]='\0';
    scanf("%d",&start);
    scanf("%d",&L);
    int len=strlen(message);
    if(start<0 ||start >=len || L<1 || start+L>len){
        printf("Invalid Input");
        return 0;
    }
    if(start<0  || start>=len || L<1 || start+ L>len){
        printf("Invalid Input");
        return 0;
    }
    for(int i=start;i<start+L;i++){
        printf("%c",message[i]);
    }
    return 0;
}