#include <stdio.h> int Check(char a , char* p) { int i = 0; while(*(p + i)) { if(a == *(p + i)) return 1; i++; } return 0; } int main() { char arr1[110] = { 0 }; char arr2[110] = { 0 }; gets(arr1); gets(arr2); int i = 0 ; while(arr1[i]) { if(Check(arr1[i] , arr2) == 0) printf("%c",arr1[i]); i++; } //thanks to bite Mr.peng return 0; }