#include <stdio.h>
#include <string.h> // Для strncpy_s

int main() {
	char string1[128];
	char string2[128];
	char string3[128];
	char string4[128];
	char character;
	int n;

	scanf("%s", &string1);
	scanf("%s", &string2);
	strcat(string1, string2);
	printf("%s\n", string1);

	scanf("%s", &string1);
	printf("enter number of copied chars\n");
	scanf("%d", &n);
	strncpy(string1, string2, n);
	printf("n symbol copied string %s\n", string2);
	printf("%s\n", string1);

	printf("enter 3d string\n");
	scanf("%s", &string3);
	printf("enter char which position you want to fiend\n");

	char * found;
	scanf("%s", &character);

	found = strchr(string3, character);
	if (found == NULL)
		printf("Symbol not found\n");
	else
		printf("The symbols position is %d\n", found - string3 + 1);

    printf("enter 4d string\n");
	scanf("%s", string4);
	char *pch = strpbrk(string3, string4);
	printf("First symbols %s\n", pch);

	int k = strcspn(string3, string4);
	printf("определить длину отрезка строки s1, не содержащего символы cтроки s2");
	printf("%s\n", k);

	return 0;
}