#include<cstdio>

int main()
{
    int A, B, C;
    scanf("%d%d%d", &A, &B, &C);
    
    for(int price=1; price <= A + 10*B; price++)
        for(int a=0; a <= A; a++)
            for(int b=0; b <= B; b++) {
                const int pay = a + b*10;
                if(pay < price) {continue;}
                const int back = A + 10*B - pay;
                const int pa = back % 10;
                const int pb = back / 10;
                const int coin = (A - a + pa) + (B - b + pb);
                if(C == coin) {
                    printf("%d", price);
                    return 0;
                }
            }
    printf("Impossible");
}