#include <stdio.h>

int main() {
    int N, A, B, Result;
    char O;
    scanf("%d", &N);
    scanf("%d", &A);
    scanf(" %c", &O);
    scanf("%d", &B);

    if(O=='+'){
        Result = A+B;
    }else{
        Result=A*B;
    }


    if(Result>N){
       printf("OVERFLOW");
    }else{
        printf("OK");
    }
    return 0;
}