#include <stdio.h>
int he(x) {
    int ans = 0;
    while (x > 0) {
        ans += x % 10;
        x /= 10;
    }
    return ans;
}

int main() {
    int n, ans = 0, i;
    scanf_s("%d", &n);
    int a[100];
    for (i = 0; i < 100; i++) {
        a[i] = 0;
    }
    for (i = 0; i <= n; i++) {
        a[he(i)] += 1;
    }
    for (i = 0; i < 100; i++) {
        ans += a[i] * a[i];
    }
    printf("%d", ans - 1);  //（0，0）不算
    return 0;
}

/sandbox/1/a.c:16:2: warning: implicit declaration of function 'scanf_s' is invalid in C99 [-Wimplicit-function-declaration]
        scanf_s("%d", &n);
        ^
1 warning generated.
/tmp/a-015a4e.o: In function `main':
a.c:(.text+0x48): undefined reference to `scanf_s'
clang: error: linker command failed with exit code 1 (use -v to see invocation)